Purification and characterization of goat pepsinogens and pepsins.
Three type-A and two type-C pepsinogens, namely, pepsinogens A-1, A-2, A-3, C-1, and C-2, were purified from adult goat abomasum. Their relative levels in abomasal mucosa were 27, 19, 14, 25, and 15%, respectively. Amino acid compositions were quite similar between isozymogens of respective types, but different between the two types especially in the Glx/Asx and Leu/Ile ratios. NH2-terminal amino acid sequences of pepsinogens A-3 and C-2 were SFFKIPLVKKKSLRQNLIEN- and LVKIPLKKFKSIRETM-, respectively. Pepsins A and C showed maximal hemoglobin-digestive activity at around pH 2 and 3, respectively, and specific activities of pepsins C were higher than those of pepsins A. Two subtypes of pepsin A were obvious, namely pepsin A-2/3 which maintains its activity in the weakly acidic pH region over pH 3 and pepsin A-1, which does not. Hydrolysis of oxidized insulin B chain by goat pepsins A occurred primarily at Ala14-Leu15 and Leu15-Tyr16 bonds.
Laboratory of Animal Management, School of Agricultural Sciences, Nagoya University, Japan.
M
M
Suzuki
Y
Y
Narita
S
S
Oda
A
A
Moriyama
O
O
Takenaka
T
T
Kageyama
D000018:Abomasum / Q000737:chemistry; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006041:Goats; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010434:Pepsin A / Q000737:chemistry / Q000302:isolation & purification*; D020116:Pepsinogen A / Q000737:chemistry / Q000302:isolation & purification*; D017386:Sequence Homology, Amino Acid
D000596:Amino Acids; D020116:Pepsinogen A; D010434:Pepsin A