Vicinal thiols are involved in inositol 1,2,3,5,6-pentakisphosphate 5-phosphatase activity from fetal calf thymus

Uday Bandyopadhyay, Thorsten Kaiser, Marco T. Rudolf, Carsten Schultz, Andreas H. Guse, Georg W. Mayr

Research output: Contribution to journalArticle

4 Scopus citations


Inositol 1,2,3,5,6-pentakisphosphate (Ins(1,2,3,5,6)P5) 5-phosphatase present in fetal calf thymus has been partially purified. This enzyme was inhibited dose-dependently by different thiol modifiers like N-ethylmaleimide (NEM), p-chloromercuribenzene sulfonate (PCMBS), diamide, and phenylarsine oxide (PAO). The inhibition by PCMBS and diamide was protected by preincubation with dithiothreitol (DTT) and the phosphatase substrate, Ins(1,2,3,5,6)P5. Diamide, a compound that specifically modifies vicinal thiol groups, also blocked the 5-phosphatase dose-dependently. Specificity of this blockade was proven by using dimercaptopropanol (DMP), a compound known to protect vicinal thiol groups. DMP prevented the enzyme from inhibition by diamide. These data suggest that vicinal thiols are involved in Ins(1,2,3,5,6)P5 5-phosphatase activity.

Original languageEnglish (US)
Pages (from-to)146-149
Number of pages4
JournalBiochemical and Biophysical Research Communications
Issue number1
Publication statusPublished - Nov 7 1997
Externally publishedYes


ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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