enzymes

1 Maria Asuncion Crispina S. Cobar MS

Maria Asuncion Crispina S. Cobar MS 2

high molecular weight proteins which

regulate the biochemical processes in

the organism

special organic catalyst , exerting a

catalytic effect on chemical reactions

In the cell, biological catalyst - substance

that increases the rate, or velocity of a

chemical reaction without itself being changed in the overall process.

special proteins produced only by living

cells

in combination with various non-protein factors, able to promote and

control with a high degree of

specificity.

Their molecular weights vary from about 9000 (hydrogenase) to

about 1,000,000.


Many enzymes will operate with

assistance of a non-protein co-factor.

CO-FACTOR water-soluble, dialyzable chemical factor which

may be :

a) simple inorganic or metallic ion =

activator

b) non protein organic cofactor =

co-enzyme

- thiamine, nicotinic acid


1. colloids, soluble in water and dilute

alcohol

2. Active at temperatures between 35o and

40o; above 65o C(presence of moisture)

3. Activity retard in the presence of certain

heavy metals, formaldehyde, and free

iodine

4. Markedly affected by pH of the medium

5. Highly selective in action


1. Ninhydrin Test

- All proteins or protein derivs. as well as ammonia, primary amines, & amides,

- presence of NH2 group is primarily responsible for this test.

- intense blue or purple colored complex is formed

- except for proline & hydroxyproline which gives a yellow color


2. Biuret test - all compounds containing two or more peptide bonds- the nitrogen of the two peptide bonds forming a violet coordination complex with cupric ions. - color varies from pink to blue depending on the number of the peptide bonds.

- negative results for dipeptides, urea, coagulated proteins and amino acids (EXCEPT serine and threonine).


3. Xanthoproteic test: - yellow color produced is due to the nitration of an aromatic ring upon heating with concentrated HNO3.

- yellow nitroderivatives form orange colored salts with NaOH or NH4OH.

- test is positive for amino acids that contain the phenyl group

- but phenylalanine responds weakly compared to hydroxyphenylalanine.


4. Millon Nasse test : - presence of phenolic groups in molecules,

which are easily nitrated by a solution of mercuric & mercurous nitrates and nitrites in conc HNO3.

- old rose color produced is probably due to a mercury complex of the nitrophenyl derivative.


5. Hopkins Cole Reaction - positive for amino acids containing the indole group.

- These indole derivatives condense with a number of aldehydes like glyoxylic acid, HOOC CHO, in the presence of strong acids to form violet colored complexes.


6. Sakaguchi Test

- depends on the presence of the guanidinium group

- In alkaline solutions, compounds containing this group combine with alpha- naphthol and sodium hypobromite (or hypochlorite) to form red or orange colored complexes.


7. Lead Acetate Test - strongly alkaline solutions, the sulfur of

the amino acid cysteine will react with lead acetate to form brown to black precipitate

- negative result for methionine, the sulfur is not readily removed by alkali hydrolysis


Classification based on action established by the Commisision on Enzymes of the Internatiional Union of Biochemistry

1. Oxidoreductases - catalyze oxidoreduction between 2 substances

- dehydrogenases, oxidases

2. Transferases catalyzing the transfer of a group other than hydrogen, between a pair of substances.

- transaminase, kinases


3. Hydrolases catalyzing jydrolysis of ester, ether, peptide, glycosyl, acid anhydride, CC , C-halide or P-N bonds

- estrases, digestive enzymes

4. Lyases catalyzing removal of groups from the substrates by mechanisms other than hydrolysis, leaving double bonds

- phospho hexo isomerase, fumarase

5. Isomerases catalyzing interconversion of optic, geometric or positional isomers

- decarboxylases, aldolases


6. Ligases catalyzing linkage of 2 compounds coupled to the breaking of a pyrophosphate bond in ATP or a similar compound.

- formation of CC, C-S, C-O, and C-N bonds by condensation reactions coupled to ATP cleavage

- Citric acid synthetase


a. Salivary diastase( ptyalin)

b. Pancreatic diastase (amylopsin)

c. Malt diastase

d. Invertase (sucrase)

e. Maltase

f. Zymase

g. Emulsin

h. Myrosin


II. Esterases III. Proteolytic Enzymes

A. Lipase A. Pepsin

B. Pectase B. Trypsin

C. Steapsin C. Erepsin

D. Urease D. Rennin

E. Papain

IV. Oxidizing Enzymes

A. Peroxidase

B. Thrombin

C. Zymase


Dried grain of one or more varieties of Hordeum vulgare L. (Poaceae)

Enzyme (maltase) converts starch to maltose stimulating growth of embryo. Grain is dried (malt or marketed as malted barley)

malt or malted barley - extensively used in brewing and alcohol industries

Containing maltose, dextrins, proteins, diastase and peptase enzyme

Used as digestive nutritive

Aid in digesting starch


Enzyme that hydrolyses lactose to galactose and glucose

Obtained from yeast, Saccharomyces lactis

Used in patients with lactose intolerance to digest lactose in milk and milk products.


Proteolytic enzyme obtained from the glandular layer of the fresh stomach of the hog, Sus scrofa L. var. domesticus (Suidae)

Pale yellow color, odorless or with a faint odor, translucent grains, slightly bitter taste

Active at 400 C pH 2 4; unstable above pH 6

Use: deficiency in gastric secretion Given after meal followed by a dose of HCl


Substance containing enzymes (amylase, lipase and protease) obtained from the pancreas of the hog, Sus scrofa L. (Suidae) or ox, Bos taurus (Bovidae)

Contain nlt 25 USP units of amylase, nlt 2 USP units of lipase, nlt 25 USP units of protease

Digestive power maybe labelled to indicate its strength in 3 minimum activities

Use: digestive aid; used in the preparation of predigested foods for invalids.

Enteric coated granules to treat infants with celiac disease


Concentrated form of pancreatin;

1 mg contain nlt 24 USP units of lipase, 100 USP units of amylase, 100 USP units of protease activity

Digestive aid (increases intestinal absorption of fat)


Dried and purified latex of the fruit of Carica papaya L. (Caricaceae)

Contains several enzymes (peptidase I, capable of converting proteins to dipeptides and polypeptides

Coagulating enzyme in milk casein

Amylolytic enzyme

Used as a digestant of proteins, employed to relieve symptoms of episiotomy

Ingredient in cleaning solution for soft contact lenses


Bromelin

Mixture of protein digesting and milk clotting enzymes from the juice of pineapple, Ananas comosus (Bromeliaceae)

Used as adjunctive therapy to reduce inflammation and edema and to accelerate tissue repair esp. in episiotomy

Effective fibrinolytic agent

Inhibit platelet aggregation


Proteolytic enzyme extracted and crystallized from the pancreas of the ox, Box taurus L. (Bovidae)

Administered in solution to the posterior chamber of the eye, under the iris, to achieve zonal lysis.


For injection

Prepared from mamalian testes , heads of leeches, snakevenoms

Mucolytic enzyme capable of depolymerizing and catalyzing hyaluronic acid and similar hexosamine containing polysaccharide


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