Identification of one- and two-chain forms of trypsinogen 1 produced by a human gastric adenocarcinoma cell line.
It has previously been reported that two kinds of human gastric adenocarcinoma cell lines (STKM-1 and MKN28) secrete a trypsin-like enzyme. In this study, four molecular forms of the enzyme (26, 25, 24 and 23 kDa on non-reducing SDS/PAGE) were purified from the serum-free conditioned medium of STKM-1 cells. Analysis of N-terminal amino acid sequences showed that the 26 kDa protein was a two-chain form of trypsinogen 1 which had been produced by proteolytic cleavage of the Arg107-Val108 bond of trypsinogen 1, and the 24 kDa protein was the one-chain form of trypsinogen 1. The 25 and 23 kDa proteins were the activated forms of the two-chain and one-chain trypsinogen 1 respectively. Isoelectric focusing gave pI values of 6.3 and 6.6 for the 26 kDa two-chain form and the 24 kDa one-chain form of trypsinogen 1 respectively. Comparison of the proteolytic activities indicated that the one-chain trypsin 1 had amidolytic activity about four times higher than that of the two-chain enzyme.
Koshikawa
N
N
Division of Cell Biology, Kihara Institute for Biological Research, Yokohama City University, Japan.
Yasumitsu
H
H
Nagashima
Y
Y
Umeda
M
M
Miyazaki
K
K
D000230:Adenocarcinoma / Q000201:enzymology*; D000595:Amino Acid Sequence; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D011487:Protein Conformation; D013274:Stomach Neoplasms / Q000201:enzymology*; D014357:Trypsin / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D014362:Trypsinogen / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D014407:Tumor Cells, Cultured
D046911:Macromolecular Substances; D010446:Peptide Fragments; D014362:Trypsinogen; D014357:Trypsin