Wróblewski H
J Bacteriol. 1981 Jan;145(1):61-7. doi: 10.1128/jb.145.1.61-67.1981.
The arrangement of the amphiphilic protein spiralin and of the other major polypeptides in the Spiroplasma citri cell membrane was investigated by one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The analyses were performed on untreated membranes for the detection of disulfide bonds and on membranes treated with dimethylsuberimidate and dithiobis(succinimidyl propionate). All membranes were depleted of the bulk of extrinsic proteins. Spiralin monomers and oligomers (mainly dimers) were detected. Almost all the oligomers appeared to be stabilized by intermolecular disulfide bonds. Components D7 (39,000 daltons), D9 (51,000 daltons), D13 (69,000 daltons), D14b (76,000 daltons), D16 (89,000 daltons), and D17 (95,000 daltons), which are the other (presumably intrinsic) main polypeptides of the S. citri membrane, were also involved in homooligomers stabilized by disulfide bonds. However, in contrast to spiralin, larger amounts of D7, D9, and D14b were involved in high-molecular-weight multimers (molecular weight, greater than 400 X 10(3) after cross-linking with dithiobis(succinimidyl propionate). Extensive cross-linking with dimethylsuberimidate showed that spiralin was the polypeptide least readily integrated to large covalent complexes. These results suggest that spiralin probably does not form a two-dimensional network in the S. citri membrane depleted of the bulk of extrinsic proteins.
通过一维和二维十二烷基硫酸钠-聚丙烯酰胺凝胶电泳研究了柑橘螺原体细胞膜中两亲性蛋白螺旋蛋白以及其他主要多肽的排列方式。分析分别在未处理的膜上进行以检测二硫键，以及在经亚胺基二甲酯和二硫代双（琥珀酰亚胺基丙酸酯）处理的膜上进行。所有膜均去除了大部分外在蛋白。检测到了螺旋蛋白单体和寡聚体（主要是二聚体）。几乎所有的寡聚体似乎都通过分子间二硫键得以稳定。组分D7（39,000道尔顿）、D9（51,000道尔顿）、D13（69,000道尔顿）、D14b（76,000道尔顿）、D16（89,000道尔顿）和D17（95,000道尔顿），它们是柑橘螺原体膜的其他（可能是内在的）主要多肽，也参与了通过二硫键稳定的同型寡聚体。然而，与螺旋蛋白不同的是，大量的D7、D9和D14b参与了高分子量多聚体（与二硫代双（琥珀酰亚胺基丙酸酯）交联后分子量大于400×10³）。用亚胺基二甲酯进行广泛交联表明，螺旋蛋白是最不容易整合到大型共价复合物中的多肽。这些结果表明，在去除了大部分外在蛋白的柑橘螺原体膜中，螺旋蛋白可能不会形成二维网络。
