An inactive cathepsin B-like enzyme and cysteine proteinase inhibitors in colon cancer ascites.
The ascitic fluid of a patient with colon cancer was found to contain an inactive cathepsin B-like enzyme. The inactive enzyme with a molecular weight of 40 kDa was converted by pepsin treatment into an active form with a molecular weight of 28 kDa as revealed by Sephadex G-75 gel chromatography. The inactive cathepsin B-like enzyme was considered to represent a precursor form and not an enzyme-inhibitor complex. The activated cathepsin B-like enzyme resembled human liver cathepsin B in its enzymatic characteristics. Cysteine proteinase inhibitor activity was also detected in the same ascitic fluid, and it was separated into two main forms by Sephadex G-75 gel chromatography. The high molecular weight inhibitor fractions reacted with antiserum against alpha-CPI and the low molecular weight fractions reacted with antiserum against cystatin B.
Matsuoka
Y
Y
Department of Physiology, Miyazaki Medical College, Japan.
Tsushima
H
H
Koga
Y
Y
Mihara
H
H
Hopsu-Havu
V K
VK
D001201:Ascites / Q000201:enzymology*; D001202:Ascitic Fluid / Q000201:enzymology; D002401:Cathepsin B / Q000032:analysis* / Q000737:chemistry; D003110:Colonic Neoplasms / Q000201:enzymology*; D015853:Cysteine Proteinase Inhibitors / Q000032:analysis* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D008875:Middle Aged; D008970:Molecular Weight; D010434:Pepsin A / Q000494:pharmacology; D012967:Sodium Dodecyl Sulfate; D013379:Substrate Specificity
D015853:Cysteine Proteinase Inhibitors; D012967:Sodium Dodecyl Sulfate; D002401:Cathepsin B; D010434:Pepsin A