Lehninger

Stryer

Γεωργάτσος

Internet

1800 Πέψη

κρέατος

και

αμύλου

από

βιολογικά

υγρά

στομάχου1850 Louis Pasteur Ζύμωση

σακχάρων, μήκυτες

απαραίτητοι

1897 Eduard Buchner υδρόλυμα

μηκύτων

Nobel 1907

1926 James Sumner καθαρισμός

ουρεάσης1930 John Northop

& Stanley κρυστάλλωσαν

pepsin & trypsin

Nobel 1946Σήμερα

πάνω

από

2000 ένζυμα

καλά

χαρακτηρισμένα

Τρισδιάστατη

δομήπρωτεϊνών

Ηλεκτρονική

πυκνότητα

Χάρτης

αντανάκλασης

Κρυσταλλογράφος

ΕΝΖΥΜΑΚΑΤΑΤΑΞΗ

ΚΑΙ

ΟΝΟΜΑΣΙΑ

ΤΩΝ

ΕΝΖΥΜΩΝ

1.

Οξειδορεδουκτάσες2.

Τρανσφεράσες

3.

Υδρολάσες4.

Λυάσες

5.

Ισομεράσες6.

Λιγάσες

Φωσφουδρολάση

ορθοφωσφορικών

μονοεστέρωνΑλκαλική

φωσφατάση

(κοινή

ονομασία)

3.1.3.13=υδρολάσες1=υδρολάσες

που

δρούν

σε

εστερικούς

δεσμούς

3= υποομάδα

που

δρα

σε

φωσφορικούς

μονοεστέρες1= ειδικό

ένζυμο

υποομάδας

3.1.3.2= όξινη

φωσφατάση

EC 1OxidoreductasesEC 1.1

Acting on the CH-OH group of donorsEC1.2

Acting on the aldehyde or oxo

group of donorsEC 1.3

Acting on the CH-CH group of donorsEC 1.4

Acting on the CH-NH2

group of donorsEC 1.5

Acting on the CH-NH group of donorsEC 1.6

Acting on NADH or NADPHEC 1.7

Acting on other nitrogenous compounds as donorsEC 1.8

Acting on a sulfur group of donorsEC 1.9

Acting on a heme group of donorsEC 1.10

Acting on diphenols

and related substances as donorsEC 1.11

Acting on a peroxide as acceptorEC 1.12

Acting on hydrogen as donorEC 1.13

Acting on single donors with incorporation of molecular oxygen (oxygenases)EC 1.14

Acting on paired donors, with incorporation or reduction of molecular oxygenEC 1.15

Acting on superoxide

radicals as acceptorEC 1.16

Oxidising metal ionsEC 1.17

Acting on CH or CH2

groupsEC 1.18

Acting on iron-sulfur proteins as donorsEC 1.19

Acting on reduced flavodoxin

as donorEC 1.20

Acting on phosphorus or arsenic in donorsEC 1.21

Acting on X-H and Y-H to form an X-Y bondEC 1.97

Other oxidoreductases

EC 2TransferasesEC 2.1Transferring one-carbon groupsEC 2.2Transferring aldehyde or ketonic

groupsEC 2.3AcyltransferasesEC 2.4GlycosyltransferasesEC 2.5Transferring alkyl or aryl groups, other than methyl groupsEC 2.6Transferring nitrogenous groupsEC 2.7Transferring phosphorus-containing groupsEC 2.8Transferring sulfur-containing groupsEC 2.9Transferring selenium-containing groupsEC 3HydrolasesEC 3.1

Acting on ester bondsEC 3.2GlycosylasesEC 3.3Acting on ether bondsEC 3.4Acting on peptide bonds (peptidases)EC 3.5Acting on carbon-nitrogen bonds, other than peptide bondsEC 3.6Acting on acid anhydridesEC 3.7Acting on carbon-carbon bondsEC 3.8Acting on halide bondsEC 3.9Acting on phosphorus-nitrogen bondsEC 3.10Acting on sulfur-nitrogen bondsEC 3.11Acting on carbon-phosphorus bondsEC 3.12Acting on sulfur-sulfur bondsEC 3.13Acting on carbon-sulfur bonds

EC 4LyasesEC 4.1Carbon-carbon lyasesEC 4.2Carbon-oxygen lyasesEC 4.3

Carbon-nitrogen lyasesEC 4.4

Carbon-sulfur lyasesEC 4.5

Carbon-halide lyasesEC 4.6

Phosphorus-oxygen lyasesEC 4.99

Other lyasesEC 5IsomerasesEC 5.1

Racemases

and epimerasesEC 5.2

cis-trans-IsomerasesEC 5.3

Intramolecular isomerasesEC 5.4

Intramolecular transferases

(mutases)EC 5.5

Intramolecular lyasesEC 5.99

Other isomerasesEC 6LigasesEC 6.1

Forming carbon—oxygen bondsEC 6.2

Forming carbon—sulfur bondsEC 6.3

Forming carbon—nitrogen bondsEC 6.4

Forming carbon—carbon

bondsEC 6.5

Forming phosphoric ester bondsEC 6.6

Forming nitrogen—metal bonds

ΟξειδορεδουκτάσεςOxidoreductase

is an enzyme

that catalyzes the transfer of electrons

from one molecule (the

reductant, also called the hydrogen acceptor or electron donor) to another (the oxidant, also called the hydrogen donor or electron acceptor). For exampleA–

+ B → A + B–

In this example, A is the reductant

(electron donor) and B is the oxidant (electron acceptor).δευδρογονάσες

καταλύουν

την

μεταφορά

υδρογόνου,

δότες

υδρογόνου

CHOH,

CHO, CHO-CH, CH-NH2, CH-NH κλπδέκτες

NAD, NADP

οξειδάσες

εάν

ο

αποδέκτης

είναι

μοριακό

οξυγόνουπεροξειδάσες

χρησιμοποιούν

το

Η2

Ο2

ως

οξειδωτικό

παράγονταυδροξυλάσες

στο

υπόστρωμα

τους

άτομα

οξυγόνου

από

μοριακό

οξυγόνο

οξυγονάσες

ενσωματώνουν

ολόκληρο

μόριο

οξυγόνου

σε

διπλούς

δεσμούς

ΤρανσφεράσεςΤransferase

is an

enzyme that catalyzes the transfer of a functional group (e.g. a

methyl or

phosphate group) from one molecule (called the donor) to another

(called the acceptor). For example, an enzyme that catalyzed this reaction would be a transferase: A–X + B → A + B–X In this example, A would be the donor, and B would be the acceptor. The donor is often a coenzymeΈνζυμα

που

μεταφέρουν

μονοανθρακικές

ομάδες, ακυλομάδες, γλυκοσυλομάδες, αζωτούχες,

φωσφορικές, θειούχες

κλπ

ΥδρολάσεςHydrolase

is an enzyme that catalyzes the hydrolysis

of a chemical bond. For example, an

enzyme that catalyzed the following reaction is a hydrolase: A–B + H2O → A–OH + B–H Διασπούν

μεγάλη

ποικιλία

δεσμών

εστεράσες, φωσφατάσες, γλυκοσιδάσες, πεπτιδάσες

Λυάσεςlyase

is an enzyme

that catalyzes the breaking of various chemical bonds

by means other than

hydrolysis

and oxidation, often forming a new double bond

or a new ring structure. For example, an enzyme that catalyzed this reaction would be a lyase: ATP

→ cAMP+ PPi

αλδολάσες

που

διασπούν

τον

δεσμό

C-C, αποκαρβοξυλάσες, κετοξυλυάσεςΙσομεράσεςisomerase

is an enzyme

that catalyses the interconversion

of polymers. Isomerases

thus catalyze

reactions of the form A → B Ρακεμάσες, επιμεράσες, cis-trans ισομεράσες

πχ

ισομεράση

της

γλυκόζης

Λιγάσεςligase

(from the Latin

verb ligāre

— "to bind" or "to glue together") is an enzyme

that can

catalyse

the joining of two large molecules by forming a new chemical bond, usually with accompanying hydrolysis

of a small chemical group pendant to one of the larger molecules.

Generally ligase

catalyses the following reaction: Ab

+ C → A–C + b or sometimesAb

+ cD

→ A–D + b + c where the lower case letters signify the small, pendant groups.

Δημιουργία

δεσμών

μεταξύ

δύο

μορίων

με

δότη

ενέργειας

ATP

Κυτοχρώματα: πρωτείνες

που

περιέχουν

αίμη, ρόλος

μεταφορά

ηλεκτρονίων, τα

πιο

γνωστά

a1

, a3

, b, c, cc1

Κυτόχρωμα

c

12400Da, 104 αμινοξέα

Δύο

δεσμοί

κυστεινών

με

τους

πυρολικούς

δακτυλίους

της

αίμης

Ι

και

ΙΙ

Αποένζυμο, ολοένζυμο, συνένζυμα

συνδέονται

στοιχειομετρικά

με

τοαποένζυμο

και

το

υπόστρωμα. Οι

βιταμίνες

εξωγενείς

διαιτητικοί

παράγοντες

Συνένζυμα

οξειδορεδουκτασών: νουκλεοτίδια

του

νικοτιναμιδίου

ΔΗ2

+ NAD+

Δ+NADH+ H+

όπου

ΔΗ2 δότης

υδρογόνου, κύριος

ρόλος

η

μεταφορά

υδρογόνου

στην

αναπνευστική

αλυσίδα

NAD+NADPΒιταμίνηνικοτιναμίδιο

Nicotinamide

adenine dinucleotide

(NAD+) is an important coenzyme

found in cells. It plays key biochemical roles as a carrier of electrons and a participant in metabolic redox

reactions, as well as in cel

signaling.

There are two forms of this coenzyme in

cells, NAD+

and the phosphorylated

form NADP+. These two related coenzymes

have

similar chemistry, but perform different roles in metabolism.

Φλαβινοσυνένζυμα

= ριβοφλαβίνη, η

αναγωγή

των

συνενζύμων

λαμβάνει

χώραμε

την

προσθήκη

υδρογόνου

στα

άτομα

Ν

*

Riboflavin (E101), also known as vitamin B2, is an easily absorbed micronutrient

with a key role in maintaining health

in animals. It is the central component of the

cofactors

FAD

and FMN, and

is therefore required by all flavoproteins. As such, vitamin B2 is required for a wide variety of cellular processes.

Like the other B

vitamins

it plays a key role in energy metabolism, and is required for the metabolism of fats, carbohydrates, and proteins.

Milk, cheese, leafy

green vegetables, liver, legumes such as mature soybeans, yeast and almonds

are good sources of vitamin B2, but exposure to light destroys riboflavin.

Άλλα

οξειδοαναγωγικά

συνένζυμα

Αίμη, ουβικινόνη

A heme

or haem

is a prosthetic group

that consists of an iron

atom contained in the center of a large heterocyclic

organic ring called a porphyrin. Not all porphyrins

contain iron, but a substantial fraction of porphyrin-containing metalloproteins

have heme as their prosthetic subunit; these are known as hemoproteins

This vitamin-like substance is, by nature, present in all human cells and responsible for the production of the body’s

own energy. In each human cell, food energy is converted into energy in the mitochondria

with the aid of CoQ10. Ninety-five percent of all the human body’s

energy requirements (ATP) is converted with the aid of CoQ10.

Therefore, those organs with the highest energy requirements –

such as the heart, the

lungs, and the liver –

have the highest

CoQ10 concentrations.

It is essential for aerobic life and a common dietary supplement. Dihydrolipoic

acid, the reduced

form of lipoic

acid, although it is sometimes also called "lipoic

acid."

One of the most visible roles of lipoic

acid is as a cofactor

in aerobic

metabolism, specifically the pyruvate

dehydrogenase complex. Lipoate

participates in transfer of

acyl

or methylamine

groups

Ασκορβικό

οξύ

Glutathione

(GSH) is a tripeptide. It contains an unusual peptide

linkage between the amine group

of cysteine

and the carboxyl

group of the glutamate

side chain. Glutathione, an antioxidant, protects cells from toxins such as free radicals.Thiol

groups are kept in a reduced

state within ~5 mM in animal

cells. In effect, glutathione reduces any disulfide bonds

formed within cytoplasmic

proteins

to cysteines

by acting as an electron

donor. Glutathione is found almost exclusively in its reduced form, since the enzyme which reverts it from its oxidized form (GSSG), glutathione reductase, is constitutively

active and inducible

upon oxidative

stress

The L-enantiomer

of ascorbic

acid is also known as vitamin C. The name "ascorbic" comes from its property of preventing and curing scurvy. Primates, including humans, and a few other species in all divisions of the animal kingdom, notably the guinea pig

have lost the ability to synthesize ascorbic

acid and must obtain it in their food.

Γλουταθειόνη

Συνένζυμα

τρανσφερασών: 1. Αδενοσινοτριφωσφορικό

οξύ-ATP

Adenosine 5'-triphosphate

(ATP) is a multifunctional

nucleotide

that is most important as a "molecular

currency" of intracellular energy

transfer. In this role, ATP transports chemical energy within cells

for metabolism. It is produced as an energy source during the processes of photosynthesis

and cellular respiration

and consumed by many enzymes

and a multitude of cellular processes including biosynthetic

reactions, motility

and cell division. In signal transduction

pathways, ATP is used as a substrate

by kinases

that phosphorylate

proteins

and lipids, as well as by adenylate

cyclase, which uses ATP to produce the second messenger

molecule cyclic AMP

Φωσφορυλιώνει

αλκόολεςR-OH + ATP R-O-P + ADPΦωσφορυλιώνει

την

γουανιδική

ομάδα

R-NH-C(NH)-NH2

+ ATP R-NH-C(NH)-NH-P + ATPΦωσφορυλιώνει

οργανικά

οξέα

R-COOH + ATP R-CO-P + ADP Πυροφωσφορυλιώνει

αλκόολες

R-OH + ATP R-O-P-P +AMP Φωσφορυλιώνει

νουκλεοτίδια

CMP + ATP CDP + ADP Αδενυλιώνει

οργανικά

οξέα

R-COOH + ATP R-CO-AMP + P-P Αδενυλιώνει

πρωτείνες

Protein-OH + ATP Protein-AMP + P-PΜεταφέρει

την

αδενοσίνη

R-S(CH3

) + ATP R-S(CH3

)-Adenosine + P-P + Pi

Ο

πιο

σημαντικός

ρόλος

του

η

φωσφορυλίωση

υποστρωμάτων

κινασών

2. Συνένζυμο

Α

ή

CoA

ή

CoA-SH μεταφέρει

ομάδες

οργανικών

οξέων.Αποτελείται

από

3’-5’

διφωσφορική

αδενοσίνη

και

φωσφορική

παντοθείνη.

Η

σπουδαιότερη

ένωση

του

το

ακέτυλο-συνένζυμο

Α

Acetyl-CoA

is an important molecule in metabolism, used in many biochemical reactions. Its main use is to convey the carbon

atoms

within the

acetyl

group to the Krebs Cycle

to be oxidized

for energy production.

3. Ενεργό

θειικό= δότης

θειικών

ομάδων

εστεροποίηση

φαινολών

στεροειδών

κλπ

4. Ενεργό

μεθύλιο

διαθέτει

την

μεθυλοομάδα

σε

άτομα

με

ελεύθερα

ηλεκτρονιακά ζεύγη

5. Ενεργό

φορμύλιο

ή

φολικό

οξύ

μεταφορέας

μονοανθρακικών

ομάδων

όπως-CH3

, -CH2

OH, -CHO στις

θέσεις

N5

και

N10

6. Ενεργό

καρβοξύλιο

ή

βιοτίνη

δεσμεύει

CO2

και

το

αποδίδεισε

αντιδράσεις

καρβοξυλίωσης

7. Πυροφωσφορική

θεαμίνη

ή

βιταμίνη

Β1

ή

θειαμίνη

δρα

ως

συνένζυμο

σε

αντιδράσειςμεταφοράς

αλδευδο

παραγώγων

8. Βιταμίνη

πυριδοξάλη

συμμετέχει

στην

μεταφορά

αμινομάδων

σε

τρανσαμινώσεις, σε

ρακεμιώσεις

και

σε

αποκαρβοξυλιώσεις

αμινοξέων

Συνένζυμα

Υδρολασών, Ισομερασών, Λυασών, Λιγασών

Κινητική

ενζυμικών

αντιδράσεων

E + S ES ES E + P

E + S ES E + Pk1

k2

k3

Industrial applications

Enzymes are used in the chemical industry

and other industrial applications when extremely specific catalysts are required. However, enzymes in general are limited in the number of reactions they have evolved to catalyse and also by their lack of stability in organic solvents

and at high temperatures. Consequently, protein engineering

is an active area of research and involves attempts to create new enzymes with novel properties, either through rational design or in vitro

evolution

Brewing industry Enzymes from barley are released during the mashing stage of beer production.They degrade starch and proteins to produce simple sugar, amino acids and peptides that are used by yeast for fermentation

Industrially produced barley enzymesWidely used in the brewing process to substitute for the natural

enzymes found in barley.Amylase, glucanases, proteases:Split polysaccharides and proteins in the malt.Betaglucanases

and arabinoxylanases:Improve the wort

and beer filtration characteristics.Amyloglucosidase

and pullulanases:Low-calorie beer

and adjustment of fermentability.Proteases: Remove cloudiness produced during storage of beers.Acetolactatedecarboxylase

(ALDC): avoid the formation of diacetyl

Baking industry Fungal

alpha-amylase enzymes are normally inactivated at about 50 degrees Celsius, but are destroyed during the baking process.

Catalyze breakdown of starch in the flour

to sugar. Yeast action on sugar produces carbon dioxide. Used in production of white bread, buns, and rolls.

ProteasesBiscuit manufacturers use them to lower the protein level of

flour.

Amylases, Xylanases, Cellulases

and ligninasesDegrade starch to lower viscosity, aiding sizing

and coating paper. Xylanases

reduce bleach required for decolorising; cellulases

smooth fibers, enhance water drainage, and promote ink removal; lipases reduce pitch and lignin-

degrading enzymes remove lignin

to soften paper.

Paper industry

Glucose Fructose

Amylases, amyloglucosideases

and glucoamylases:Converts starch

into glucose

and various syrupsGlucose isomerase:

Converts glucose

into fructose

in production of high fructose syrups

from starchy materials. These syrups have enhanced sweetening

properties and lower calorific values

than sucrose for the same level of sweetness

Starch industry

Dairy industryRennin

derived from the stomachs of young ruminant animals

manufacture of cheese, used to hydrolyze

proteinMicrobially

produced enzyme increasing use in the dairy industry.

Lipases

is implemented during the production of Roquefort cheese

to enhance the ripening of the blue-mould cheese.

Lactases Break down lactose

to glucose

and galactose

Papain

To soften meat for cooking

Restriction enzymes, DNA ligase

and polymerases

Used to manipulate DNA in genetic engineering, important in pharmacology, agriculture

and medicine. Essential for restriction digestion

and the polymerase chain reaction. Molecular biology is also important in forensic science.

Molecular biology

Proteases:

produced in an extracellular

form from bacteria

Used for presoak conditions and direct liquid applications helping with removal of protein stains from clothesAmylases: Detergents for machine dish washing to remove resistant starch residues.

Lipases:

Used to assist in the removal of fatty and oily stains

Cellulases:

Used in biological fabric conditioners

Cellulases:

Used to break down cellulose into sugars that can be fermented

Detergents

Biofuel

industry

One example is the most common type of phenylketonuria. A mutation of a single amino acid in the enzyme phenylalanine hydroxylase, which catalyzes the first step in the degradation of phenylalanine, results in build-up of phenylalanine and related products. This can lead to mental retardation

if the disease is untreated

Phenylalanine hydroxylase

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με

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