Wood J S, Yan X, Mendelow M, Corbin J D, Francis S H, Lawrence D S
Department of Chemistry, State University of New York, Buffalo 14260, USA.
J Biol Chem. 1996 Jan 5;271(1):174-9. doi: 10.1074/jbc.271.1.174.
The cAMP-dependent (PKA) and cGMP-dependent protein kinases (PKG) share a strong primary sequence homology within their respective active site regions. Not surprisingly, these enzymes also exhibit overlapping substrate specificities, a feature that often interferes with efforts to elucidate their distinct biological roles. In this report, we demonstrate that PKA and PKG exhibit dramatically different behavior with respect to the phosphorylation of alpha-substituted alcohols. Although PKA will phosphorylate only residues that contain an alpha-center configuration analogous to that found in L-serine, PKG utilizes residues that correspond to both L- and D-serine as substrates. The PKG/PKA selectivity of these substrates is the highest ever reported.
环磷酸腺苷依赖性（蛋白激酶A，PKA）和环磷酸鸟苷依赖性蛋白激酶（蛋白激酶G，PKG）在各自的活性位点区域内具有很强的一级序列同源性。不出所料，这些酶还表现出重叠的底物特异性，这一特征常常干扰阐明它们独特生物学作用的努力。在本报告中，我们证明，就α-取代醇的磷酸化而言，PKA和PKG表现出显著不同的行为。虽然PKA仅会磷酸化含有与L-丝氨酸中发现的α-中心构型类似的残基，但PKG将与L-丝氨酸和D-丝氨酸对应的残基都用作底物。这些底物的PKG/PKA选择性是迄今报道的最高值。
