Abstract
Procathepsin H in kidney and liver microsomal lumen was identified to have a molecular mass of 41 kDa by immunoblot analysis. The proenzyme was then concentrated by applying the microsomal contents to a concanavalin A-Sepharose column. When the concanavalin A-adsorbed fraction was incubated at pH 4.0 at 20 °C, the activity measured with synthetic substrate increased 3.5 times over that of the control after 24 h incubation. Immunoblot analysis showed that acidic treatment caused the disappearance of procathepsin H. Thus the proenzyme might be processed to the mature enzyme under acidic conditions. The marked increase of enzymatic activity and the conversion of proenzyme were completely blocked with pepstatin which is a potent inhibitor of aspartic proteases. These results suggested that a protease for processing procathepsin H might be cathepsin D, a major lysosomal aspartic protease. Therefore, procathepsin H seems to be synthesized first in the enzymatically inactive form in endoplasmic reticulum and successively converted into the active form in lysosomes during biosynthesis.
| Original language | English |
|---|---|
| Pages (from-to) | 712-718 |
| Number of pages | 7 |
| Journal | Archives of Biochemistry and Biophysics |
| Volume | 260 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 1 1988 |
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All Science Journal Classification (ASJC) codes
- Biophysics
- Biochemistry
- Molecular Biology
Cite this
Identification of latent procathepsin H in microsomal lumen : Characterization of proteolytic processing and enzyme activation. / Nishimura, Yukio; Kato, Keitaro.
In: Archives of Biochemistry and Biophysics, Vol. 260, No. 2, 01.02.1988, p. 712-718.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Identification of latent procathepsin H in microsomal lumen
T2 - Characterization of proteolytic processing and enzyme activation
AU - Nishimura, Yukio
AU - Kato, Keitaro
PY - 1988/2/1
Y1 - 1988/2/1
N2 - Procathepsin H in kidney and liver microsomal lumen was identified to have a molecular mass of 41 kDa by immunoblot analysis. The proenzyme was then concentrated by applying the microsomal contents to a concanavalin A-Sepharose column. When the concanavalin A-adsorbed fraction was incubated at pH 4.0 at 20 °C, the activity measured with synthetic substrate increased 3.5 times over that of the control after 24 h incubation. Immunoblot analysis showed that acidic treatment caused the disappearance of procathepsin H. Thus the proenzyme might be processed to the mature enzyme under acidic conditions. The marked increase of enzymatic activity and the conversion of proenzyme were completely blocked with pepstatin which is a potent inhibitor of aspartic proteases. These results suggested that a protease for processing procathepsin H might be cathepsin D, a major lysosomal aspartic protease. Therefore, procathepsin H seems to be synthesized first in the enzymatically inactive form in endoplasmic reticulum and successively converted into the active form in lysosomes during biosynthesis.
AB - Procathepsin H in kidney and liver microsomal lumen was identified to have a molecular mass of 41 kDa by immunoblot analysis. The proenzyme was then concentrated by applying the microsomal contents to a concanavalin A-Sepharose column. When the concanavalin A-adsorbed fraction was incubated at pH 4.0 at 20 °C, the activity measured with synthetic substrate increased 3.5 times over that of the control after 24 h incubation. Immunoblot analysis showed that acidic treatment caused the disappearance of procathepsin H. Thus the proenzyme might be processed to the mature enzyme under acidic conditions. The marked increase of enzymatic activity and the conversion of proenzyme were completely blocked with pepstatin which is a potent inhibitor of aspartic proteases. These results suggested that a protease for processing procathepsin H might be cathepsin D, a major lysosomal aspartic protease. Therefore, procathepsin H seems to be synthesized first in the enzymatically inactive form in endoplasmic reticulum and successively converted into the active form in lysosomes during biosynthesis.
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UR - http://www.scopus.com/inward/citedby.url?scp=0023955872&partnerID=8YFLogxK
U2 - 10.1016/0003-9861(88)90500-0
DO - 10.1016/0003-9861(88)90500-0
M3 - Article
C2 - 3277536
AN - SCOPUS:0023955872
VL - 260
SP - 712
EP - 718
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -