Some features of the Streptococcus faecalis Na+‐ATPase resemble thoseof the vacuolar‐type ATPases

[摘要]

In the ethylenediaminetetraacetic acid (EDTA) extract prepared from the membranes of Streptococcus faecalis, we found the 330-kDa protein that was coordinately increased with the induction of Na⁺-ATPase. It was missed in the EDTA extract of Nakl, a mutant defective in the Na⁺-ATPase, but restored in that of its revertant, NaklR. The 330-kDa protein showed the ATP hydrolytic activity by active staining, and mainly consisted of the polypeptides of 73 kDa, 52 kDa and possibly 38 kDa. In addition, the Na⁺-stimulated ATPase of the membranes was sensitive to both nitrate and N-ethylmaleimide, inhibitors for the vacuolar H⁺-ATPase. Thus, the Na⁺-ATPase of this organism has a structure similar to vacuolar H⁺-ATPase.

[学科分类] 生物化学/生物物理

[关键词] Na+-ATPase;Vacuolar ATPase;Induction;Streptococcus faecalis;EDTA;ethylenediaminetetraacetic acid;PAGE;polyacrylamide gel electrophoresis;SDS;sodium dodecyl sulfate;NEM;N-ethylmaleimide