Removal of protein interference in the Fiske-SubbaRow method by sodium dodecyl sulfate

✍ Scribed by Yohtalou Tashima

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 258 KB
• Volume: 69
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(75)90143-8

✦ Synopsis

In kinetic studies on erythrocyte membrane ATPase, the activity is assayed by following the release of orthophosphate from ATP by the Fiske-SubbaRow method. The deproteinization of the samples, which is essential before assay by this method, is an obstacle to the quick and efficient assay of large numbers of samples. Nonionic detergents, e.g., Lubrol, which are used in the purification of Na+-K+-ATPase from plasma membranes, also interfere strongly with the Fiske-SubbaRow method.

It was found that the addition of sodium dodecyl sulfate to the samples before the orthophosphate assay solubilized much of the membrane protein, allowing orthophosphate to be determined by the Fiske-SubbaRow method without the deproteinization step. Sodium dodecyl sulfate and the solubilized proteins did not interfere with the determination. The addition of sodium dodecyl sulfate was also found to abolish the interference of nonionic detergents with the Fiske-Sub-baRow determination. As a result, the assay of erythrocyte membrane ATPase could be greatly simplified. 410