| Summary: | 碩士 === 國立陽明大學 === 生物化學研究所 === 91 === Endogenous Protein phosphatases play significant roles in signal transduction pathways pertaining to metabolism, contractility, membrane transport and secretion, gene expression, cell proliferation, fertilization, neurotransmission, and even memory.
Protein phosphatase-1 (PP-1) is one of the serine/threonine protein phosphatases and is regulated by several heat-stable proteins, including inhibitor-1 (I-1), inhibitor-2 (I-2) and, DARPP-32 (dopamine and cAMP-regulated phosphoprotein, Mr. 32,000). Recently, two new isoforms of cDNA for inhibitor-1 have been cloned and identified from human brain and liver by RT-PCR (Liu et. al., Biochem. Biophys. Res Comm. 291, 1293-1296 (2002)). Inhibitor-1 (I-1) is one of the two new isoforms. It was derived from alternative splicing product of inhibitor-1 gene with an in-frame 51 residues being deleted. The deletion occurred from residue 84 to residue 134 of inhibitor-1. Inhibitor-1 is a 120 amino acid protein with a molecular mass about 13 kDa
In this study we have employed nuclear magnetic resonance (NMR) spectroscopy to determine the solution structure of inhibitor-1. A series of heteronuclear multi-dimensional NMR experiments have been performed on 13C and/or 15N labeled I-1 Form these spectra, we have obtained near-complete backbone 1H, 13C and 15N resonance assignments of I-1he assignments have been deposited in the BioMagResBank under BMRB accession number 5904. The results of consensus chemical shift index (CSI) analysis suggest that one short -helix is located atGlu23—Arg30. The rest of the molecule has a random coil conformation.
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