Vorgias C E, Traub P
Z Naturforsch C J Biosci. 1986 Sep-Oct;41(9-10):897-909. doi: 10.1515/znc-1986-9-1016.
In analogy to experimental results previously obtained with vimentin and neurofilament triplet proteins, the intermediate filament (IF) proteins desmin and glial fibrillary acidic protein (GFAP) were also found to have high capacities to associate with nucleic acids. Employing a collection of native and heat-denatured pro- and eukaryotic DNAs, a series of naturally occurring single-stranded (ss)RNAs and a variety of synthetic polynucleotides of the RNA and DNA type, both proteins could be shown to bind preferentially to single-stranded polynucleotides. In the case of ssDNA and synthetic polyribonucleotides, a clear dependency of the binding activity on the G-content of the nucleic acids was demonstrated. The interaction of desmin with ssDNA and tRNA was characterized by strong cooperativity. When a mixture of desmin and vimentin was offered to excess ssDNA, the cooperativity effect brought about segregation of both protein species into two distinct populations of deoxyribonucleoprotein particles with substantially different sedimentation rates; this segregation is in sharp contrast to the ability of desmin and vimentin to form heteropolymers in filament assembly. In general, desmin and GFAP were found to be similar to vimentin and neurofilament proteins in their nucleic acid-binding properties. However, there were also striking differences between individual non-epithelial IF proteins at this level.
与先前用波形蛋白和神经丝三联体蛋白获得的实验结果类似，中间丝（IF）蛋白结蛋白和胶质纤维酸性蛋白（GFAP）也被发现具有与核酸结合的高能力。利用一系列天然和热变性的原核和真核DNA、一系列天然存在的单链（ss）RNA以及各种RNA和DNA类型的合成多核苷酸，发现这两种蛋白都能优先结合单链多核苷酸。在ssDNA和合成多聚核糖核苷酸的情况下，证明了结合活性对核酸G含量的明显依赖性。结蛋白与ssDNA和tRNA的相互作用具有很强的协同性。当将结蛋白和波形蛋白的混合物提供给过量的ssDNA时，协同效应导致两种蛋白物种分离成具有明显不同沉降速率的两个不同的脱氧核糖核蛋白颗粒群体；这种分离与结蛋白和波形蛋白在细丝组装中形成异源聚合物的能力形成鲜明对比。一般来说，发现结蛋白和GFAP在核酸结合特性方面与波形蛋白和神经丝蛋白相似。然而，在这一水平上，各个非上皮IF蛋白之间也存在显著差异。
