Pepsin A Explained

Pepsin A
Ec Number:	3.4.23.1
Cas Number:	9001-75-6
Width:	270

Pepsin A (pepsin, lactated pepsin, pepsin fortior, fundus-pepsin, elixir lactate of pepsin, P I, lactated pepsin elixir, P II, pepsin R, pepsin D) is an enzyme.^{[1] [2] [3] [4] [5] [6] [7]} This enzyme catalyses the following chemical reaction

Preferential cleavage: hydrophobic, preferably aromatic, residues in P1 and P1' positions. Cleaves Phe¹-Val, Gln⁴-His, Glu¹³-Ala, Ala¹⁴-Leu, Leu¹⁵-Tyr, Tyr¹⁶-Leu, Gly²³-Phe, Phe²⁴-Phe and Phe²⁵-Tyr bonds in the B chain of insulin

The enzyme is a predominant endopeptidase in the gastric juice of vertebrates.

See also

• Pepsin

Notes and References

1. Lee D, Ryle AP . Pepsinogen D. A fourth proteolytic zymogen from pig gastric mucosa . The Biochemical Journal . 104 . 3 . 735–41 . September 1967 . 4167464 . 1271213 .
2. Lee D, Ryle AP . Pepsin D. A minor component of commercial pepsin preparations . The Biochemical Journal . 104 . 3 . 742–8 . September 1967 . 4860638 . 1271214 .
3. Foltmann B . Gastric proteinases--structure, function, evolution and mechanism of action . Essays in Biochemistry . 17 . 52–84 . 1981 . 6795036 .
4. James MN, Sielecki AR . Molecular structure of an aspartic proteinase zymogen, porcine pepsinogen, at 1.8 A resolution . Nature . 319 . 6048 . 33–8 . 1986 . 3941737 . 10.1038/319033a0 .
5. Book: Aspartyl proteinases . New Comprehensive Biochemistry: Hydrolytic Enzymes . Fruton, J.S. . 1987 . 16 . 1–38 . Neuberger, A. . Brocklehurst, K. . Elsevier . Amsterdam .
6. Tang J, Wong RN . Evolution in the structure and function of aspartic proteases . Journal of Cellular Biochemistry . 33 . 1 . 53–63 . January 1987 . 3546346 . 10.1002/jcb.240330106 .
7. Pohl J, Dunn BM . Secondary enzyme-substrate interactions: kinetic evidence for ionic interactions between substrate side chains and the pepsin active site . Biochemistry . 27 . 13 . 4827–34 . June 1988 . 3139029 . 10.1021/bi00413a037 .