Abstract
New method for purification of phosphatase inhibitor 1 (PPI-1) was developed which avoid the phosphorylation of PPI-1 during the purification and provides a high yield of highly pure preparation. Using this preparation, it was shown that PPI-1 was stoichiometrically phosphorylated by cGMP-dependent protein kinase at Thr-35 and the phosphorylated PPI-1 potently inhibited protein phosphatase 1. Addition of the phosphorylated PPI-1 to β-escin-skinned single smooth muscle cells resulted in force development of the cells at the submaximal pCa2+. The results suggest that the phosphorylation of PPI-1 can be the mechanism for modifying the Ca2+ sensitivity of smooth muscle contractile response.
Original language | English (US) |
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Pages (from-to) | 777-783 |
Number of pages | 7 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 220 |
Issue number | 3 |
DOIs | |
State | Published - Mar 27 1996 |
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology