What kind of pepsin available?
What is Pepsin ?
What is the application?
What kind of pepsin available?
Product |
Product code |
Quality |
Pepsin NF |
1:3000 powder |
|
1:3000 granular |
||
1:10000 powder |
||
1:10000 granular |
||
1:15000 powder |
||
1:15000 granular |
||
Higher power. powder |
||
Higher power. granular |
||
Pepsin EP |
0.5 Eur. Ph. powder |
|
0.5 Eur. Ph. granular |
||
1.6 Eur. Ph. powder |
||
1.6 Eur. Ph. granular |
||
2.5 Eur. Ph. powder |
||
2.5 Eur. Ph. granular |
||
Higher power powder |
||
Higher power granular |
||
Pepsin BP |
1:3000 powder |
|
1:3000 granular |
||
1:10000 powder |
||
1:10000 granular |
||
1:15000 powder |
||
1:15000 granular |
||
Pepsin JP |
3800~6000 powder |
|
3800~6000 granular |
||
Pepsin CP |
3800 powder |
Customized qualities are available upon request.
What is Pepsin ?
Source: Porcine gastric mucosa
Systematic name: Peptidyl peptide hydrolase
Other name Pepsin A
CAS-No. 9001-75-6
E.C.-No. 3.4.23.1
Occurrence
Acid proteinases are found in the gastric juice of mammals and have been reported in the juice of birds, amphibia and fishes. The major enzyme from the pig, pepsin A, is a single polypeptide of 327 residues and is formed by cleavage of 44 residues from the amino terminus of pepsinogen A; one or more of the peptide fragments removed inhibit the activity of pepsin A and other acid proteinases at pH values above 5. Besides having proteinase and peptidase activity, pepsin can catalyze the hydrolysis of suitable depsipeptids (ester analogues of peptides) and even of sulphite esters. (1)
Characteristics
Composition: Pepsin has a law alpha-helical structure content. The protein configuration of the crystalline form is that of a compact nearly spherical molecule, the structure being maintained by hydrophobic bonds. The amino acid analysis shows a high content of aspartic acid, glutamic acid, and serine whereas the content of the basic amino acids is unusually low. This explains that pepsin even in 0.1 N HCl is still a negative ion. (2).
Specificity: Almost all high molecular weight proteins are attacked by Pepsin; exceptions are keratins, mucins, ovomucoid, silk fibroin, spongin, protaminases and protein hydrolysis products of low molecular weight. Certain chemical substrates of low molecular weight are hydrolysed, particularly peptides containing in close proximity aromatic residues, tyrosine and cysteine, including for instance carbobenzoxy-L-glutamyl-L-tyrosine and L-histidine. The presence of two carboxyl groups is necessary for pepsin action on synthetic substrates. If both of the carboxyl groups are masked then pepsin will not split the resulting compound. (2)
Effectors: Pepsin reacts more slowly than other proteinases on protein substrates and even more slowly on peptides. Generally, proteolysis by pepsin is greatly favoured if an aromatic ring is present in the side-chain of either of the amino acids on both sides of the bond hydrolyzed. The amino group may involve a tyrosine or a phenylalanine residue. When both involved residues are aromatic, these are split even more rapidly than any others. (2)
Catalytic optima: The optimum pH of activity on proteins is between 1.6 and 1.8 and is narrower for crystalline pepsin than for a crude preparation.
Below pH 5, the conversion of pepsinogen is effected by pepsin in an autocatalytic process that involves the removal of the 41-residue amino terminal portion of the zymogene. Several low molecular weight products are formed, including an inhibitory peptide composed of 29 amino acid residues. This inhibitor, which was obtained in crystalline form, is bound to pepsin at pH 5; at more acid pH values, dissociation of the pepsin-inhibitor complex is favoured, and the peptide is cleaved. The rate of activation is optimal at pH 2, is first-order with respect to both pepsinogen and pepsin, and is increased by the addition of inorganic salts. (2)
Stability of solution: Pepsin is in aqueous solution at pH 5-5.5 relative stable. The stability is higher in Glycerine. Pepsin is irreversible inactivated in alkaline medium.
Solubility: freely soluble in water, insoluble in most organic solvents.
Molecular weight: 34500 Daltons. (4)
Isoelectric point: pH 1.0 (3)
Isoionic point: 2.2-3.0 (3)
Spectral data: E280 (1%, 1cm) = 14.7 (3)
What is the application?
Applications/Uses:
* Nutritional formulas (tablets/capsules/powders) as a digestive aid
* Food/Cheese manufacturing
* Hydrolysis of proteins
* Animal Health formulas as a digestive aid
* Meat tenderizing formulas