Samanta B, Mezö G, Das K P, Ghose A C, Hudecz F, Sen P C
Department of Chemistry, Bose Institute, Kolkata, India.
J Pept Res. 2005 Apr;65(4):445-9. doi: 10.1111/j.1399-3011.2005.00235.x.
Protein kinase (PK) A catalytic (PKAcat) subunit was purified to homogeneity from bovine lens using a 100-kDa cut-off membrane filtration followed by different chromatographic procedures. The molecular weight of PKAcat was found to be 41 kDa. The kinase phosphorylates histone IIIs and other synthetic modified peptides of VRKRTLRRL with different amino acid environment. The extent of phosphorylation depends not only on the presence of Ser or Thr (phosphorylating residues) but also on other surrounding amino acid residues. Although some peptides compete in phosphorylating histone, they are not very significant. The result suggests that the extent of phosphorylation depends on the amino acid residue(s) surrounding phosphorylable residue(s) on the peptide.
使用截留分子量为100 kDa的膜过滤，随后采用不同的色谱方法，从牛晶状体中纯化出了蛋白激酶（PK）A催化（PKAcat）亚基，使其达到了均一性。发现PKAcat的分子量为41 kDa。该激酶可磷酸化组蛋白IIIs以及VRKRTLRRL具有不同氨基酸环境的其他合成修饰肽段。磷酸化程度不仅取决于丝氨酸或苏氨酸（磷酸化残基）的存在，还取决于其他周围的氨基酸残基。尽管一些肽段在磷酸化组蛋白方面存在竞争，但它们的影响并不十分显著。结果表明，磷酸化程度取决于肽段上可磷酸化残基周围的氨基酸残基。
