The selective role of cathepsins B and D in the lysosomal degradation of endogenous and exogenous proteins

FEBS Letters

Katunuma, Nobuhiko¹  Kominami, Eiki²  Ueno, Takashi²  Muno, Daisaku² 

[1]Division of Enzyme Chemistry, Institute for Enzyme Research, The University of Tokushima, Kuramoto-cho 3-18-15, Tokushima-shi, Tokushima 770, Japan

[2]Department of Biochemistry, School of Medicine, Juntendo University, Hongo 2-1-1, Bunkyo-ku, Tokyo 113, Japan

关键词: Cysteine proteinase inhibitory E-64 derivative;    Pepstatin;    Leupeptin;    Cathepsin B;    Cathepsin L;    Cathepsin D;    z;    benzoyloxycarbonyl;    MCA;    methylcournarylamide;    BCA;    bicinchoninic acid;    CA-074;    N-(L-3-trans-propylcarbamoyloxirane-2-carbonyl)-L-isoleucyl-L-proline;    FITC;    fluorescein isothiocyanate;   

DOI  :  10.1016/0014-5793(91)80048-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A selective inhibitor of cathepsin B, a derivative of E-64 (compound CA-074), and pepstatin-asialofetuin, a potent inhibitor of cathepsin D, were used for an in vivo study of the selective role of these proteinases in lysosomal proteolysis. Administration of compound CA-074 or pepstatinasialofetuin to rats caused only a slight shift of the lysosomal density and no increase in sequestered enzymes in the autolysosomal fraction, although cathepsin B or D activity in the liver was markedly inhibited. These treatments also had little effect on the inhibition of the degradation of endocytosed FITC-labeled asialofetuin. In contrast, leupeptin treatment caused marked inhibition of lysosomal degradation of endogenous and exogenous proteins. These results suggest a small contribution of cathepsins B and D to the initiation of lysosomal proteolysis.

【 授权许可】

Unknown