Enders G L, Duncan C L
Can J Microbiol. 1976 Sep;22(9):1410-4. doi: 10.1139/m76-209.
Polyacrylamide gel electrophoresis of highly purified Clostridium perfringens enterotoxin revealed electrophoretic microheterogeneity of the enterotoxin, apparently because of slight charge differences in the peptides. Detergent gel electrophoresis showed that purified enterotoxin formed high molecular weight aggregates in the presence of both sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide. No conditions capable of inhibiting this phenomenon were found. Although a molecular weight of 35 000 daltons has been reported in the literature, the experimentally determined molecular weight values in the presence of detergents corresponded to multiples of a theoretical subunit molecular weight of 17 500 daltons. Binding studies performed by equilibrium dialysis and ultracentrifugation methods revealed that the enterotoxin bound very small amounts of SDS per gram of protein. The evidence presented indicates possible detergent induced structural alterations of the protein.
对高度纯化的产气荚膜梭菌肠毒素进行聚丙烯酰胺凝胶电泳，结果显示该肠毒素存在电泳微异质性，这显然是由于肽段的电荷略有差异所致。去污剂凝胶电泳表明，在十二烷基硫酸钠（SDS）和十六烷基三甲基溴化铵存在的情况下，纯化的肠毒素会形成高分子量聚集体。未发现能够抑制这种现象的条件。尽管文献报道该肠毒素的分子量为35000道尔顿，但在去污剂存在下通过实验测定的分子量值相当于理论亚基分子量17500道尔顿的倍数。通过平衡透析和超速离心法进行的结合研究表明，每克蛋白质的肠毒素结合的SDS量非常少。所提供的证据表明蛋白质可能发生了去污剂诱导的结构改变。
