Wistow G, Roquemore E, Kim H S
Laboratory of Molecular and Developmental Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892.
Curr Eye Res. 1991 Apr;10(4):313-9. doi: 10.3109/02713689108996337.
In soluble extracts of bird lenses, crystallin subunits of apparent sizes between 30kDa and 40kDa show considerable variability in both abundance and mobility in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). This is only partly due to the taxon-specific distribution of lactate dehydrogenase-B (LDH-B)/epsilon-crystallin. Here we show that, in spite of high conservation in primary sequence, beta B1-crystallin subunits of avian lenses have a markedly slower migration in SDS PAGE than those of mammals and that the apparent subunit size of beta B1-crystallin varies among birds. This may be at least partly due to unusual post-translational modifications, since beta B1-crystallins of adult birds react strongly in a glycan detection procedure. No other crystallins in birds or mammals share this strong reaction. Modification of beta B1-crystallin could have interesting consequences for the formation of high molecular weight beta-crystallin aggregates in bird lenses.
在鸟类晶状体的可溶性提取物中，表观大小在30kDa至40kDa之间的晶状体蛋白亚基在十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）中的丰度和迁移率都有相当大的变异性。这只是部分归因于乳酸脱氢酶-B（LDH-B）/ε-晶状体蛋白的分类群特异性分布。在此我们表明，尽管鸟类晶状体βB1-晶状体蛋白亚基的一级序列高度保守，但在SDS-PAGE中的迁移速度明显比哺乳动物的慢，并且βB1-晶状体蛋白的表观亚基大小在鸟类中也有所不同。这可能至少部分归因于不寻常的翻译后修饰，因为成年鸟类的βB1-晶状体蛋白在聚糖检测过程中反应强烈。鸟类或哺乳动物中的其他晶状体蛋白都没有这种强烈反应。βB1-晶状体蛋白的修饰可能会对鸟类晶状体中高分子量β-晶状体蛋白聚集体的形成产生有趣的影响。
