Monkey pepsinogens and pepsins. Monkey pepsinogens and pepsins. V. Purification, Characterization, and amino-terminal sequence determination of crab-eating monkey pepsinogens and pepsins

J Biochem. 1980 Sep;88(3):635-45. doi: 10.1093/oxfordjournals.jbchem.a133014.


Pepsinogens were purified from the gastric mucosa of the crab-eating monkey, Macaca fascicularis. Eight pepsinogens were shown to be present disc-electrophoretically and they were termed pepsinogens I-a, I-b, III-1-a, III-1-b, III-2-a, III-2-b, III-3, and C, based on the nomenclature used for Japanese monkey pepsinogens. The molecular weights were 43,000 for pepsinogens I-a and I-b, 40,000 for pepsinogens III-1-a, III-1-b, III-2-a, III-2-b, and III-3, and 38,000 for pepsinogen C, as determined by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis. Pepsinogens I-a and I-b contained carbohydrate amounting to about 4-5% by weight. Each was activated to pepsin by acidification at pH 2.0. Pepsinogen III-1 (a mixture of III-1-a and III-1-b) yielded a single pepsin, i.e. pepsin III-1, and pepsinogen III-2 (a mixture of III-2-a and III-2-b) also gave a single pepsin, i.e. pepsin III-2. The molecular weights were estimated to be 38,000 for pepsins I-a and I-b, 35,000 for pepsins III-1, III-2, and III-3, and 34,000 for pepsin C. Optimal pHs toward acid-denatured hemoglobin were 1.9, 2.3, 2.0, 2.0, and 2.3 for pepsins I-a, III-1, III-2, III-3, and C, respectively. Pepstatin, diazoacetyl-DL-norleucine methyl ester (DAN), 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP), and p-bromophenacyl bromide inhibited each pepsin. Amino acid compositions of the pepsinogens and pepsins were determined. Pepsinogen C and pepsin C were distinct from the other pepsinogens and pepsins in their high ratios of glutamic acid to aspartic acid, and leucine to isoleucine. Amino acid sequences of the amino (N)-terminal 14 residues of pepsinogens were determined by the manual Edman procedure. One to three substitutions of amino acids were observed in the 14-residue segments among the pepsinogens except for pepsinogen C. There were 7 amino acid substitutions between pepsinogens C and III-3. These results suggest that the amino acid substitutions in the N-terminal region contribute considerably to the heterogeneity of pepsinogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Gastric Mucosa / enzymology*
  • Hydrogen-Ion Concentration
  • Macaca fascicularis
  • Molecular Weight
  • Pepsin A / metabolism*
  • Pepsinogens / isolation & purification
  • Pepsinogens / metabolism*


  • Pepsinogens
  • Pepsin A