History of enzymes

History of Enzyme

Assoc. Prof. Dr. Somporn Tanskul
Department of Molecular Biotechnology and Bioinformatics

Faculty of Science
Prince of Songkla University

Hat Yai

Ribozyme

catalyze specific reaction
no RNA translation
named “ribozyme”

digest and/ or bind phosphodiester bond
RNA (RNA moiety) as a target
Tetrahymena ribozyme
Hammerhead ribozyme
Hairpin ribozyme

Enzyme

Wine fermentation
Bread making in Egypt

“Fermentation occurred from living things or
chemical substance”
1897 Eduard Buchner

the extract from yeast can change sugar to alcohol
the extract called zymase

Embden, Meyerhof “Embden Meyerhof pathway”

1926 urease extraction from Jack beans
urease

Eduard Buchner

protein plays an important role in fermentation

5 years later (1902) Franz Hofmeister

polypeptide consists of various kinds of atoms
linked by peptide bonds

Protein can be found in bacteria, viruses, eukaryotes.

more than 50% of dry weight of cells
more than other biomolecules
involved in one specific chemical reaction
and biological systems

1839 Gerhardus Johannes Mulder
C, H, O, N (S, P) in fibril, albumin and gelatin

Protein comes from “Primarius (latin)” or “Proteus(Greek)”

1828 Friedrich Wöhler
ammonium cyanate
heat
isomer of urea, urea

1873 Heinrich Hlasiwetz and Josef Habermann

Building blocks of proteins are amino acids.

casein
strong acid or base

glutamic acid, aspartic acid, leucine and ammonia

other proteins
strong acid or base

different kinds of amino acids

1897 Eduard Buchner

function of protein
Emil Fischer

enzyme
……

Cells contains various kinds of enzymes.
1902 Franz Hofmeister

Amino acids were aligned within polypeptide chains.
1926 James Batcheller Sumner

Urease could be precipitated.

1954 Linus Carl Pauling
nature and characteristics of peptide bonds

Protein

building block of protein is amino acid
peptide
polypeptide

Protein can be found in all living things.

The kinds of protein

globular proteins
fibrous proteins: collagen, keratin
conjugated proteins: metalloproteins,

glycoproteins, nucleoproteins

Coenzyme and Oxidation-reduction reactions

Some kinds of oxidation-reduction reactions need
a cofactor.

A cofactor is a non-protein chemical compound or
metallic ion that is required for an enzyme's
activity as a catalyst, a substance that increases
the rate of a chemical reaction.

Cofactors can be considered "helper molecules"
that assist in biochemical transformations.

Coenzymes are mostly derived from vitamins and
other organic essential nutrients in small
amounts.

Coenzymes are further divided into two types.

The first is called a "prosthetic group", which consists of
a coenzyme that is tightly or even covalently, and
permanently bound to a protein.

The second type of coenzymes are called
"cosubstrates", and are transiently bound to the protein.
Cosubstrates may be released from a protein at some
point, and then rebind later.

Holoenzyme = protein (enzyme) + prosthetic group
= An apoenzyme together with its cofactor.
A holoenzyme is complete and catalytically active.

Apoenzyme = protein (enzyme)

An apoenzyme is an inactive enzyme, activation
of the enzyme occurs upon binding of an organic
or inorganic cofactor.

The source of enzymes

Advantages of using enzymes
specificity
efficiency
mild condition
safe

Specificity of enzymes

chemoselectivity
regioselectivity
differentiate enantiomers (L, D form of amino
acids)

Efficiency of enzymes
Enzymes can transform substrate to
product(s).
The velocity of product formation.

The Michaelis Constant and Enzyme Efficiency

the velocity at which product accumulates,v
a function of the rate constant for this reaction, k2,
the concentration of ES present, expressed as [ES]

The higher the rate constant and the more substrate-
enzyme complex present, the more rapidly the
ultimate product of the reaction accumulates.
Therefore:

v = k2[ES]

Enzyme working under mild conditions

Enzymes are safe.

No problems after using in food
Digestability
Glucose oxidase in mayonnaise
Glucose oxidase preventing changes in color

and taste during storage.

Disadvantages of using enzymes

Unstable
High price
Loss of activity

Enzymes
Unstable
hydrogen bond

ionic bond/ electrostatic interaction
van der Waals force or interaction
hydrophobic interaction (HI)
Unfavorable conditions
pH

foam
high temperature
organic solvent
High price

Safety and regulatory aspects of enzyme use
GRAS (Generally Regarded as Safe)
FDA (Food and Drug Administration)

Classification of enzymes

Classified by the Enzyme Commission (E.C.)
IUPAC (International Union of Pure and

Applied Chemistry)
IUB (International Union of Biochemistry)

Enzymes divided into 6 groups

The first figure of E.C.

E.C. 1 oxidoreductase
E.C. 2 transferase
E.C. 3 hydrolase
E.C. 4 lyase
E.C. 5 isomerase
E.C. 6 ligase or synthetase

Ex

EC1 oxidoreductase
EC1.1 react with donor CH-OH
EC 1.1.1 react with NAD or NADP of acceptor
EC 1.1.3 react with O2 or acceptor

EC2 transferase
EC2.1 transfer C1
EC2.1.1 transfer methyl group
EC2.1.2 transfer hydroxymethyl and formyl group

Questions