Enzyme

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„Ribbon diagram” of the enzyme Triosephosphatisomerase (TIM) the Glycolyse, a representative rp and wiski representation of the protein structure, won through X-ray structure analysis. The TIM is considered as catalytically perfect enzyme (see enzyme kinetics).

An enzyme (become outdated of Greek εν~, en~ „in” and ζύμη, zýmeSauerteig”: Enzyme) is a protein, which catalyzes a chemical reaction. Enzymes playa basic role in the metabolism of all living organisms, nearly all biochemical reactions, of digesting (example:Pepsin) up to copying the heiress formation (DNA polymerase), are catalyzed and steered by enzymes.


Table of contents

designation and organization

nomenclature after IUPAC and IUBMB

the IUPAC and internationally union OFBiochemistry and Molecular Biology (IUBMB [1]) compiled together a nomenclature of the enzymes, which containing group of the molecules classifies these heterogeneous and numerous representatives. For this the IUPAC compiled principles of the nomenclature:

  • Enzyme names end up - ase, if it itself notaround several enzymes in a system acts. (Example: Hydrol ase.)
  • the enzyme name should be explaining, thus the reaction, which catalyzes the enzyme, describes (example: Cholinesterase: an enzyme, which the group of esters in the Cholin - molecule hydrolyzes.)
  • the enzyme name is its classification (see above) contain. (Example: Cholin esterase.)

in addition was developed a code system ( see input clutch numbers), in which the enzymes under a numeric code from four numbers are to be found. The first number designates the enzyme class. Lists of allseized enzymes ensure a faster finding of the indicated enzyme code. The codes orient themselves at characteristics of the reaction, which catalyzes the enzyme, in practice prove to numeric codes however as unmanageable. More frequently to be used systematic names, after that aboverules mentioned were conceived. Problems of the nomenclature result for instance in the case of enzymes, which catalyze several reactions. Therefore sometimes for it several names exist. Some enzymes carry trivial names, which do not show that it itself with the substance mentioned around enzymesacts. Since these names found however traditionally a broad use, they were partly maintained. (Examples: the digesting enzymes Trypsin and Pepsin of humans.)

classification after IUPAC and IUBMB

of enzymes become according to the reaction in six, catalyzed by themEnzyme classes divided (see also input clutch number):

  1. Oxidoreduktasen, which catalyze redox reactions.
  2. Transferasen, which transfer functional groups from a substrate to another.
  3. Hydrolase, which split connections using water.
  4. Lyasen, also Synthasen mentioned, those splittingor synthesis of more complex products of simple substrates catalyze, however without splitting of ATP.
  5. Isomerasen, which accelerate the transformation of chemical isomers.
  6. Ligasen or Synthetasen, which catalyze the formation of substances, which are chemically more complex than the usedSubstrates, however in contrast to the Synthasen only under energy consumption, i.e. by ATP splitting, are enzymatically effective.

Some enzymes are able several to catalyze partially very different reactions. If this is the case, then become this severalEnzyme classes added.

structure

of enzymes can be differentiated on the basis their structure. While many enzymes consist of only one protein chain, so-called monomers, form other enzymes Oligomere from several protein chains, for the subunits. Some enzymes store themselves with furtherTogether and cooperate to enzymes to so-called multi-enzyme complexes with one another or adjust themselves mutually. Turned around there are also individual protein chains, which contain several enzyme activities (multi-functional enzymes). A further possible organization regarding its structure considers the presence of Cofaktoren:

  • Holoenzyme consist of a protein portion, the Apoenzym,as well as from a Cofaktor. Both together are important for the function of the enzyme. Organic molecules as Cofaktoren are called Coenzyme and are often descendants of Vitaminen. If they are kovalent bound to the Apoenzym, one calls them prosthetische groups. Needs an enzyme metal ions (z. B. ), One speaks iron, zinc or copper ions of a Metalloenzym.

enzymes

chemical reactions accelerate function as biocatalysts, by lowering the activation energy, which must be overcome, thus it to oneMaterial conversion comes. Theoretically an enzymatic conversion is reversible, D. h. the products can be converted again into the basic materials. The basic materials (Edukte) of an enzyme reaction, which becomes substrates, in the active center so mentioned of the enzyme bound, imagines itself Enzyme substrate complex. The enzyme makes now the transformation possible of the substrates into the reaction products, which are set free afterwards from the complex. Like all catalysts the enzyme is present after the reaction again in the output form. Enzymes draw by high substrate and they only the suitable substrates select and catalyze reaction specificity out, under numerous materials exactly one of many conceivable reactions.


energetic bases of the catalysis

Energiediagramm einer enzymatischen Reaktion: Die Aktivierungsenergie (freie Aktivierungsenthalpie) wird im Vergleich zur unkatalysiert Reaktionen durch Stabilisierung des Übergangszustandes gesenkt. Die freie Reaktionsenthalpie dagegen bleibt unverändert.
energy diagram of an enzymatic reaction: The activation energy (free activation enthalpy) becomes in the comparison tounkatalysiert reactions by stabilization of the transient condition lowered. The free reaction enthalpy against it remains unchanged.

Most biochemical reactions would not run off without enzymes practically at all or only extremely slowly. Enzymes increase the reaction rate of such reactions by several orders of magnitude, it make possible thusonly a functioning metabolism. Important is however the following: An enzyme can in no case reactions take place let, which are energetically forbidden, i.e. their products energetically more highly than the basic materials (substrates). As with each spontaneous reaction running off must thosefree reaction enthalpy (<math> \ delta G< /math>) negatively its. The chemical equilibrium is not changed by the enzyme, probably however the speed, with which it adjusts itself. The catalytic effectiveness of an enzyme is based only on its ability, the activation energy <math> (\ delta G^ {\ more ddagger})< to /math>a chemicalTo lower reaction. The activation energy is the amount of energy, which must be first overcome, in order to set the reaction on. During the reaction the substrate is changed increasingly, it takes an energetically unfavorable transient condition. The activation energy is now thatAmount of energy is needed, in order to force the substrate into the transient condition. Here the catalytic effect of the enzyme sets: Through reciprocal effects with the transient condition stabilizes it not kovalente these, so that less energy one needs, around the substrate into thatTo bring transient condition. The substrate can be converted substantially faster into the reaction product, since it to a certain extent a way becomes smoothed „”.

the active center - structural basis for catalysis and specificity

for the catalytic effectiveness of a protein enzyme is the active center responsible. Here the substrate binds and thereafter „actively” is converted. The active center consists of folded parts of the Polypeptidkette or reactive non--protein portions (Kofaktoren) of the enzyme molecule. A special hollow structure in the enzyme causes that the active centerwith a structurally fitting substrate into contact to step can. It comes to the formation of an enzyme substrate complex. Like a key into the associated lock, then a certain substrate fits the appropriate enzyme (key lock principle). Herein also „the key lies” toothe high substrate specificity of the enzymes. Already small structural differences can lead to the fact that the substrate similar a material no more than substrate is not recognized. Hexokinase for example does not accept glucose as substrate, the related Galactose however. Other enzymes possess a broaderSubstrate specificity, z. B. diminish alcohol Dehydrogenasen beside ethanol also different alcohols. The recognition and connection of the Subtrats succeed through not kovalente to reciprocal effects (hydrogen bonds, electrostatic reciprocal effect or hydrophobe effects) between parts of the enzyme and the substrate. Falsely obtain thatKey lock model the conception, the substrate and enzyme are rigid thing. The enzyme actually often changes its shape with the connection of the substrate, whereby the connection partners come to each other only into the necessary proximity and spatial situation. One speaks with this kind thatRecognition of induced fit or induced adjustment. The connection of the enzyme does not have to be strong enough, in order to bind the often small concentrated substrate (micro to millimolecular concentrations), it may however to strongly be, there the reaction not with thatConnection of the substrate ends. A still stronger connection of the transient condition of the reaction and thus its stabilization is important. Pretty often two substrates participate in a reaction, the enzyme must then the correct orientation of the reaction partners to each other guarantee. Latter mechanisticalPeculiarities of an enzymatic reaction are the basis of the effect specificity of an enzyme. It catalyzes in each case one of many conceivable reactions of the substrates.

catalytic strategies

although the mechanisms of enzymatic reactions in the detail are multiform, use enzymes in thatRule or several of the following catalytic strategies:

  • Preferred connection of the transient condition:

The connection of the transient condition is stronger than the connection of the substrates and products, from this a stabilization of the transient condition results.

  • Orientation and approximation of substrates:

The connection of two substratesin suitable orientation and Konformation the reaction rate can increase substantially, since the reactive groups of the molecules come to each other into the correct situation and are stabilized for the reaction favorable Konformationen of the molecules.

  • General acid Basen catalysis:

Amino acid residues z. B. of Histidin react as acid or a cousin, by it during a reaction protons (H + - ions) take up or deliver.

  • Kovalente catalysis:

Amino acid residues or Coenzyme are received kovalente connections with a substrate and to form a short-lived Intermediat (intermediate product). In thatRule are with such reactions nukleophile amino acid side chains (for example Lysin - Seitenketten with amino group) or Coenzyme such as Pyridoxalphosphat takes part.

  • Metal ion catalysis:

Metal ions know the catalysis as structure-stabilizing co-ordination centers , redox partners (often iron - or copper - ions) or as Lewis acids (frequent zinc - ions)support. They can stabilize negative charges and/or. shield or water molecules activate.

enzyme kinetics

reaction rate and enzyme activity

enzyme kinetics concerns itself with the laws, which describe the course of enzymatic reactions. A central size here is the reaction rate. It is a measure for the change of the substrate concentration with the time, thus for the amount of material substrate, which is converted in a certain reaction volume per time unit (unit: <math> mol*l^ {- 1} s^ {- 1}< /math>). Apart from the reaction conditions such as temperature, salt concentration and pH value thatSolution, depends it on the concentrations of the enzyme, the substrates and products as well as on the presence on Effektoren (activators or inhibitors).

In connection with the reaction rate the enzyme activity stands. The activity is a size, which the quantity of activeEnzyme in an enzyme preparation reflects. The units of the enzyme activity are unit (U) and Katal (kat), whereby 1 U is defined as that quantity enzyme, which converts a micro mol substrate per minute under indicated conditions: 1 U = 1 µmol/min. Katalone uses rarely, is however the SI-UNIT of the enzyme activity: 1 kat = 1 mol/s. The quality of an enzyme preparation can be read off from the specific activity (activity per Masseneinheit, U/mg). The measured enzyme activity is proportionally to the reaction rate and sensitive like thesedependent on the reaction conditions: The enzyme activity rises with the temperature according to the RGT rule: An increase of the temperature over approx. 5-10 °C leads to a duplication of the reaction rate. This applies however only to a limited temperature range. With exceeding of an optimalTemperature comes it to steep dropping of the activity by denaturing the enzyme. Changes in the pH value of the solution have often dramatic effects on the enzyme activity: Usually a pH optimum, a pH value exists with that the highest activity is measured. Already smallDeviations can bring the enzyme activity to succumbing. Something similar applies to the salt concentration and/or. the ion strength in the environment.

Michaelis Menten theory

a proven model for the kinetic description of simple enzyme reactions is the Michaelis Menten theory (mm theory). It supplies a connection between that Initial speed v 0 of an enzyme reaction as well as the enzyme and substrate concentration [E 0] and [S]. When one designates initial speed (Initiationsgeschwindigkeit) the reaction rate, which is observed, before considerable quantities of product formed. The mm equation reads as follows:

<math> v_0= {k_ {cat} [E_ {0}] [S] \ over K_m + [S]} </math>

The parameters K m (Michaeliskonstante) and k cat (Wechselzahl) are suitable to characterize enzymes kinetic D. h. To meet statements about their catalytic efficiency. An important result thatMm theory is the occurrence of a saturation: With increasing substrate concentrations the initial speed rises first, approaches however sometime an upper limit value on (hyperbolic process). In the condition of the saturation all active centers of the enzymes are working at full capacity „”.

 Sättigungshyperbel
Saturation hyperbola

thoseMm theory is based in a simple model of the enzyme substrate complex:

Enzymkinetik: k2 = kcat

(Only) a substrate S reacts in a Gleichgewichtsreaktion with the free enzyme E to an enzyme substrate complex IT. The quantity k 1 designates the education rate, k -1 the purge rate of the complex.The it complex disintegrates besides with the rate k 2, whereby beside the product P the enzyme in its output form is set free. A backward reaction of the product is not considered, since as previously mentioned the initial speed of the reaction is to be determined.In order to deduce from the explained river equation a mathematical connection in form of the Michaelis Menten equation, one avails oneself of a simplification: The concentration of the it complex is accepted as constant during the reaction (flow equilibrium, also steady state). For the parameters K m and k cat applies then:

<math> k_ {} =k_2 /math< cat> and <math> K_m= {k_ {- 1} + k_2 \ over k_1} </math>. Although the mm model represents a strong simplification of the actual reaction mechanisms, it is in practice very useful, in order to characterize a multiplicity from enzymes to. Also thoseEffect of restrictors can be discussed in the context of the mm model.

catalytic efficiency

the catalytic efficiency of an enzyme can be characterized in the context of the Michaelis Menten model by different sizes. The Wechselzahl k cat corresponds to the number of the converted substrate moleculesper second and enzyme molecule under substrate saturation. The Katalase sets under „full extent of utilization” for example approx. 10.000.000 molecules per second over (Lit.: Voet, S.480). The product of enzyme concentration and Wechselzahl supplies the maximum speed <math> v_ {to max} = k_ {cat} * [E_0]< /math with>. With small substrate concentrationsthe specificity constant is <cat> math k_ {} \ over K_m< /math> a more suitable measure for the catalytic efficiency. Reaches it values of more than <math> 10^8< /math> until <math> 10^9 M^ {- 1} s^ {- 1}< /math>, the reaction rate only limited by the diffusion of the substrate and enzyme molecules. Each coincidental contact ofEnzyme and substrate lead to a reaction. One calls enzymes, which reach such an efficiency, „catalytically perfectly”. Apart from the Katalase the Triosephosphatisomerase and the acetylcholinesterase are mentioned as examples. Since the active center constitutes only a small part of the enzyme surface,assumes one mechanisms, which direct the substrate into the active center. Such „attracting mechanism” becomes following the Greek legend world as Circe - effect designation and is possibly present with the Superoxiddismutase. In the living cell metabolic pathways become often through Substrate canalization accelerates. As at „the assembly-line” materials are passed on within multi-enzyme complexes from an enzyme to the next.

regularization

Kooperativität and Allosterie

some enzymes do not show the hyperbolic saturation curve, how it predicts the Michaelis Menten theory, but sigmoides satisfying us behavior. Sigmoides binding behavior was described with binding proteins like hemoglobin and is interpreted for the first time as positive Kooperativität of several connection places: The connection places, often located in different subunits, affect each other mutually in its connection ability (affinity). With a positive Kooperativitätstrengthens the connection of the ligand (e.g. the substrate) the affinity of further connection places. A binding protein with many free connection places has a weaker affinity than a to a large extent besetzes protein. If the same ligand binds to all connection centers, one speaks of a homotropen effect.The Kooperativität is closely linked with the term of the Allosterie with enzymes. By Allosterie one understands the presence of further connection places in an enzyme, apart from the active center, the allosterischen centers. Bind regulatorische substances (Effektoren), which are different from the substrate,to allosterische centers, a heterotroper effect is present . The Allosterie is to be differentiated conceptually from the cooperative phenomena to, yet they arise often together. The allosterischen enzymes are important Schaltstellen with the regularization and control of the enzyme activity in the organism.

multi-substrate reactions

the past considerations apply only to reactions, in which only one substrate is involved. Many enzymes catalyze however the reaction of two or several substrates and/or. Kosubstrate. The same applies to the product side, it can thus alsoseveral products to be formed. With reversible reactions the distinction between substrate and product is anyway relative. The Michaelis Menten theory applies to one of several substrates only, if the enzyme is satisfied with the other substrates.

Ein Enzym katalysiert eine Reaktion zweier Substrate zu einem Produkt. Erfolgt die Bindung des Substrats 1 stets vor der Bindung des Substrats 2, so liegt ein geordneter sequenzieller Mechanismus vor.
An enzyme catalyzes a reaction of twoSubstrates to a product. If the connection of the substrate 1 always takes place before the connection of the substrate 2, then an arranged sequenzieller mechanism is present .

For multi-substrate reactions the following mechanisms are conceivable:

  • Sequenzielle mechanisms:

The substrates bind successively to the enzyme. Creditall substrates bound, a central complex is present . In this the transformation of the substrates takes place to the products, which will dismiss in sequence afterwards from the complex. One differentiates thereby between:

    • Coincidence mechanisms (English. random):

The sequence thatSubstrate connection is coincidental.

    • Arranged mechanisms (English. ordered):

The sequence of the connection is fixed.

  • Ping Pong mechanisms:

The connection of substrate and the release of product take place alternating. First for example substrate A binds to the enzyme, and becomes into the first productP converted, whereby a part of the substrate A at the enzyme remains and the enzyme leaves P. Then the second substrate B is taken up and reacted with the enzyme-bound remainder from A to a second product Q, which as the latter set freebecomes.

enzyme inhibition

as enzyme inhibition (inhibition) one designates the reduction of the catalytic activity of an enzyme by a specific restrictor (inhibitor). There are different types of the enzyme inhibition, which differ in its effect mechanism.

Irreversible inhibition

some medicaments and poisons restrain an enzyme durably and unreversible, one speak also of irreversible inhibition. The connection of the inhibitor can be kovalenter nature or a very strong not kovalente connection. With the so-called suicide inhibitors it acts overSubstances, which are recognized first by the enzyme as substrate and taken up to the active center. There they however a firm kovalente connection with amino acid residues of the active center are received, whereby this is durably blocked. Figurativy the enzyme spoke throughthe admission of the inhibitor „suicide” committed. A well-known suicide inhibitor is the antibiotic penicillin, which can switch an enzyme off of the bacterial cell wall synthesis irreversibly.

reversible inhibition

the so-called reversible enzyme inhibition is in principle reversible and plays with the fine regularizationthe metabolism in living organisms a crucial role. A reversible inhibitor forms an enzyme inhibitor complex with the enzyme in a Gleichgewichtsreaktion. This shows either decreased activity (partial inhibition) or no activity (complete inhibition). Due to different mechanisms those leaves itself(complete) reversible inhibition into further Untertypen divide:

  • Kompetitive inhibition
with the kompetitiven inhibition competes the substrate with the restrictor around the connection to the active center of the enzyme. Both can bind not at the same time to the enzyme. The inhibitor is inContrast to the substrate however enzymatically convertible and does not stop thereby the enzyme work. Increasing concentrations of the inhibitor lead to an increasing displacement of the substrate and thus to a reduction of the enzyme activity. An increase of the substrate concentration turns this procedure and makes possiblean increased substrate conversion.
  • Unkompetitive inhibition
the restrictor can bind exclusively to the enzyme substrate complex, not to the free enzyme. Connection of the restrictor prevents the catalytic conversion of the substrate to the product.
  • not kompetitive inhibition
the restrictor binds both to the free enzyme andalso to the enzyme substrate complex. The enzyme substrate inhibitor complex is catalytically inactive.

Another organization, which stands apart from the mechanistical organization discussed above, regards the connection place of the inhibitor:

  • Isosteri inhibition
the restrictor binds to the active center of the enzyme. The kompetitive inhibition is usually isosterisch.
  • Allosteri inhibition
during the allosterischen inhibition binds the restrictor to a second connection place in the enzyme, which is different from the active center, a allosterisches center. The connection of the restrictor to the allosterische center stabilizes a Konformation of theEnzyme with lowered or shut down catalytic activity. The allosterische inhibition is of great importance with the metabolic regularization. With as final product inhibition (feedback inhibition) the well-known regularization the final product of a metabolic pathway works as allosterischer inhibitor of the first enzyme of the same way.

Regularization and control of the enzyme activity in the organism

of enzymes cooperate in the living organism in a complex network of metabolic pathways. In order to be able to adapt to varying internal and outside conditions optimally, are a fine regularization and control of the metabolism and a thatunderlying enzymes necessarily. By regularization one understands procedures, which serve the maintenance of stable internal conditions under changing environmental condition (homeostasis). Control one calls changes, those due to of external signals (z. B. Hormones) take place. There are snaps/short term, medium-termas well as slow/long-term regularization and control procedures in the metabolism:

short term adjustment

fast changes of the enzyme activity take place as direct answer of the enzymes to changed concentrations of Stoffwechselprodukten, like substrates, products or Effektoren (activators and inhibitors). Enzyme reactions, the close at the equilibriumlie, react sensitively to changes of the substrate and product concentrations. Accumulation of substrate accelerates the forward reaction, accumulation of product restrains the forward reaction and promotes the backward reaction (kompetitive product inhibition). However the irreversible enzyme reactions a larger role becomes general with thatMetabolic regularization and control attributed.

Of great importance one is the allosterische regularization. Substrate or Effektormoleküle, which results in the metabolism, binds to allosterische centers of the enzyme and changes its catalytic activity. Allosteri enzymes consist of several subunits (either from same oralso from different protein molecules). The connection of substrate or restrictor molecules to a subunit leads to Konformationsänderungen in the entire enzyme, which change the affinity of the remaining connection places for the substrate. A final product inhibition (feedback inhibition) develops, if the product of a reaction chainthe enzyme at the beginning of this chain allosterisch restraining affects. Thus automatically an automatic control loop develops.

medium-term adjustment

a frequent form of metabolic control is the kovalente modification of enzymes, particularly the phosphorylation. As by a molecularSwitch can be switched on or off the enzyme for example after a hormoneal signal by phosphate-transferring enzymes (Kinasen). The introduction of a negatively charged group of phosphates draws structural changes in the enzyme and can active in principle and inactive Konformationenfavour. The splitting off of the group of phosphates by Phosphatasen turns around this procedure, so that a flexible adjustment of the metabolism is possible to changing physiological requirements.

long-term adjustment

as long-term reaction to changed requirements of the metabolism enzymes becomeaimed diminished or newly formed. The new formation of enzymes is steered via the Expression of its genes. Such a kind of the genetic regularization with bacteria describes the opera on model of Jacob and Monod. The controlled dismantling of enzymes in eukaryontischen cells can be realized by Ubiquitinierung. Attaching Polyubiquitin chains to enzymes, catalyzed by specific Ubiquitin Ligasen, marks these for the dismantling in the Proteasom, one „Müllschlucker” of the cell.

occurrences and use of enzymes

of enzymes are valuable tools that Biotechnology. Their application type reach from the cheese production (lab enzyme) up to the genetic engineering. For certain applications scientists develop today aimed more efficient enzymes by protein engineering. Besides one designed a new form of catalytically active proteins, the catalytic anti-bodies, which were called due to their similarity to the enzymes Abzyme. Also Ribonukleinsäuren (RNA) can be catalytically active; these are then called Ribozyme.

In our body hundreds of different enzymes work. Many enzymes are in the Cytoplasma of the cells. Numerous ones of them sit in the bio diaphragms, which pull this Cytoplasma through. Others can work also outside of the cells in body cavities, as the digesting enzymes in the Darmtrakt. An enzyme is missing or is not not active it approximately by Vitaminmangel,it can come to heavy metabolic disturbances. In addition, enzymes are needed by the industry.Detergents adds one Lipasen (fat splitting enzymes), Proteasen (protein splitting enzymes) and Amylasen (strength splitting enzymes) for the increase of the cleaning achievement, because these enzymesappropriate marks decompose. Enzymes are used also for the production of some medicines and insect protective agents. In the cheese production the lab enzyme participates , an enzyme, which was won from calf stomachs. Many enzymes can be manufactured today by genetically changed micro organisms.

In the medicine enzymes play an important role. Many medicaments restrain enzymes or strengthen their effect, in order to heal an illness. Most prominent representative of such medicine materials is probably the acetylsalicylic acid, those the enzyme Cyclooxygenase restrains and thus among other things schmerzlinderndworks.

Many poisonings are to be led on the inhibition of enzymes back. Most heavy metals work malicious by their restraining effect on enzymes. Also the probably most well-known poison cyanogen potash affects restraining an enzyme system.

meaning of enzymesin the medical diagnostics

the diagnostics uses enzymes, in order to discover diseases. In the Teststreifen for Diabetiker is for example an enzyme system, which produces a material , whose content can be measured under effect of blood sugar. Thus indirectly that becomesBlood sugar mirror measured. One calls this proceeding a “enzymatic measurement”. It is used also in medical laboratories, z. B. to the regulation of glucose (blood sugar) or alcohol. Enzymatic measurements are to be used relative simply and low-priced. One makes oneself thereby the substrate specificity ofEnzymes too use. An enzyme is thus added to the body fluid which can be analyzed, which can specifically convert the substrate which can be measured. From the developed quantity of reaction products one can read off then, how much from the substrate in the body fluid was present.

In the human blood are also a set of enzymes measurable on the basis their activity directly. In the blood circulating enzymes partial individual organs come of. Therefore conclusions on damages of certain organs can do on the basis the degradation or increase of enzyme activities in the bloodare pulled. So z can. B. a pancreas inflammation by the strongly increased activity of the Lipase and the Pankreas Amylase in the blood to be recognized.


scientific history of the enzymes

the most important scientist, who was concerned with enzymes, was thatGerman chemists Otto Röhm. It developed procedures for the enzymatic LED suppl. inheriting, Fruchtsaftreiniung as well as a number of diagnostic applications.

literature

general:

  • Mountain, Tymoczko, Stryer: Biochemistry. 5. Edition. Spectrum academic publishing house, Heidelberg Berlin 2003, ISBN 3-8274-1303-6
  • Donald Voet, Judith G. Voet: Biochemistry, 3rd edition (Wiley internationally edition), John Wiley & Sons Inc., the USA 2004, ISBN 0-471-39223-5
  • Rainer Stürmer, Michael Breuer: Enzymes as catalysts. Chemistry and biology hand in hand. Chemistry in our time 40 (2), S. 104 - 111 (2006),ISSN 0009-2851


Silierung:

  • Mike Woolford: The Silage fermentation Microbiology Series. Volume., 14. , MARCEL DEKKER, New York, 1984, ISBN 0-8247-7039-0

enzyme kinetics and enzyme inhibition:

  • Hans Bisswanger: Enzyme kinetics. 3. Edition. WILEY VCH publishing house, Weinheim 2000, ISBN 3-527-30096-1

regularization and control:

  • David skin: Understanding theControl OF Metabolism. Haven country press Ltd., London 1997 Reprinted 2003, ISBN 1-85578-047-X

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