Identification and characterization of the core region of protein phosphatase-1

摘要: PP1, PP2A and PP2B all belong to PPP family of serine/threonine protein phosphatases. Their primary structures are highly conserved, particularly in the catalytic domain. In order obtain correlative information about this conserved region, we constructed N-, C-deletion N/C double-deletion mutants. We found that N- Csingle-deletion mutants exhibited higher enzymatic activities, while specific activity mutant PP1 (9-306) did not notably change. The results kinetics analysis showed kcat kcat/Km increased 16-fold single-deletion mutants; two parameters were lower than single-deletions. further explored stability existing denaturant guanidine hydrochloride (GdnHCl). It was noticeable PP1-(9-306) highest. speculated maybe retains a compact spherical structure, thus accordingly affected molecular catalysis. On other hand relatively relaxed, which able bind substrate easily, so activities mutant. therefore deduced may be close core region molecule. solidify idea, used fluorescence spectra method explore changes space conformation. emission peaks single-deletions blue shifted different degree absence denaturant, peak change obviously compared with wild-type PP1. Conformation significantly less those GdnHCl concentration.