Possible involvement of cathepsin L in processing of rat liver hexokinase to eliminate mitochondria-binding ability.
A previously found proteinase possibly involved in the modification of hexokinase to eliminate the mitochondria-binding ability without appreciable change in the catalytic activity (called hexokinase-processing enzyme hereafter), was purified by sequential chromatographies from rat liver and its properties were examined. The hexokinase-processing enzyme had carbohydrate moieties as evidenced by adsorption on immobilized concanavalin A, and had a molecular weight of about 23,000 as estimated by SDS-PAGE and gel filtration chromatography. Benzyloxycarbonyl-phenylalanyl-L-arginine-4-methylcoumaryl-7-amide (Z-Phe-Arg-MCA)-hydrolyzing activity was co-purified with this processing activity throughout the purification, while the hydrolyzing activity for benzyloxycarbonyl-L-arginyl-L-arginine-4-methylcoumaryl-7-amide (Z-Arg-Arg-MCA) was not. The processing activity, as well as Z-Phe-Arg-MCA hydrolyzing activity, was highly sensitive to cysteine proteinase inhibition, for example, by leupeptin and N-[N-3-(trans-carboxirane-2-carbonyl)-L-leucyl]agmatine (E-64). Furthermore, the enzyme preparation reacted with an antibody against cathepsin L purified from rat kidney. These results indicated that cathepsin L may be involved in the above-mentioned processing of hexokinase.
Okazaki
H
H
Department of Physiological Chemistry, Hiroshima University School of Medicine.
Tani
C
C
Ando
M
M
Ishii
K
K
Ishibashi
S
S
Nishimura
Y
Y
Kato
K
K
D000818:Animals; D001665:Binding Sites; D056668:Cathepsin L; D002403:Cathepsins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D003374:Coumarins; D003546:Cysteine Endopeptidases; D004151:Dipeptides; D010450:Endopeptidases; D005456:Fluorescent Dyes; D006593:Hexokinase / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational; D051381:Rats; D013379:Substrate Specificity
D003374:Coumarins; D004151:Dipeptides; D005456:Fluorescent Dyes; C021159:benzyloxycarbonyl-phenylalanylarginine-4-methylcoumaryl-7-amide; D006593:Hexokinase; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D056668:Cathepsin L; C534280:Ctsl protein, rat