Sergeev Y V, Chirgadze Y N, Mylvaganam S E, Driessen H, Slingsby C, Blundell T L
Institute of Protein Research, Academy of Sciences of the USSR, Pushchino, Moscow Region.
Proteins. 1988;4(2):137-47. doi: 10.1002/prot.340040207.
A comparative study of intermolecular interactions in crystals of two homologous low molecular weight proteins, gamma-II and gamma-IIIb crystallins, from calf eye lens was carried out. Crystal packings for these proteins are very different: intermolecular contact areas compose about 33% of the total accessible surface area of gamma-II as compared with 13% in gamma-III. Two key residues seem to be mainly responsible for the differences in protein association in the crystal medium. These are Ser 103 and Leu 155 in gamma-II, which are replaced by Met 103 and His 155 in gamma-IIb. A similar substitution of these residues is observed in different gene products of gamma-crystallins from a number of vertebrates. This is consistent with the existence of a genetically controlled mechanism for determining intermolecular association of gamma-crystallins in the native medium of the lens.
对来自小牛眼晶状体的两种同源低分子量蛋白质γ-II和γ-IIIb晶状体蛋白晶体中的分子间相互作用进行了比较研究。这些蛋白质的晶体堆积非常不同：γ-II的分子间接触面积约占总可及表面积的33%，而γ-IIIb中这一比例为13%。两个关键残基似乎是造成晶体介质中蛋白质缔合差异的主要原因。它们是γ-II中的Ser 103和Leu 155，在γ-IIIb中被Met 103和His 155取代。在许多脊椎动物的γ-晶状体蛋白的不同基因产物中也观察到了这些残基的类似取代。这与存在一种遗传控制机制来决定γ-晶状体蛋白在晶状体天然介质中的分子间缔合是一致的。
