Chondroitin sulfate proteoglycan is a potent enhancer in the processing of procathepsin L.
The acceleration effect of chondroitin-4-sulfate(CS-) proteoglycan on the processing of procathepsin L in vitro was investigated using enzyme purified from the culture medium of MLC cells. Procathepsin L was slightly processed even when it was incubated without CS-proteoglycan for 60 min in 50 mm acetate buffer, pH 5.5, and trace amounts of the 31 kDa mature form and 35-38 kDa intermediates of cathepsin L were formed. On the other hand, in the presence of CS-proteoglycan, procathepsin L was completely converted to the mature form within the same 60 minute time period. Moreover, Z-Phe-Arg-MCA hydrolyzing activity was increased significantly by the incubation with CS-proteoglycan, while no considerable increase in the activity was observed during the incubation without CS-proteoglycan. Since the specific cathepsin L inhibitor, CLIK-195, inhibited the processing of procathepsin L accelerated by CS-proteoglycan, the trace amount of cathepsin L activity may participate in the processing. These results suggest that CS-proteoglycan may play a role in accelerating the processing of procathepsin L as an endogenous enhancer in the extracellular environment in vivo.
Kihara
Motohiro
M
Faculty of Health and Living Science, Naruto University of Education, Naruto 772-8502, Japan.
Kakegawa
Hisao
H
Matano
Yuko
Y
Murata
Etsuko
E
Tsuge
Hideaki
H
Kido
Hiroshi
H
Katunuma
Nobuhiko
N
D000818:Animals; D015153:Blotting, Western; D056668:Cathepsin L; D002403:Cathepsins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D002460:Cell Line; D011508:Chondroitin Sulfate Proteoglycans / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D051381:Rats; D013268:Stimulation, Chemical
D011508:Chondroitin Sulfate Proteoglycans; D004792:Enzyme Precursors; D002403:Cathepsins; C063905:procathepsin L; D056668:Cathepsin L