Guanidine hydrochloride-induced changes of the E2 inner core of the Bacillus stearothermophilus pyruvate dehydrogenase complex

Yasuaki Hiromasa, Yoichi Aso, Kouta Mayanagi, Yorinao Inoue, Tetsuro Fujisawa, Kohji Meno, Tatzuo Ueki

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The limited proteolysis of the Bacillus stearothermophilus pyruvate dehydrogenase complex by V8 protease yields its core structure solely composed of lipoate acetyltransferase (E2) fragments. The changes in the core with guanidine hydrochloride (GdnHCl) were biphasic: below 0.8 M (first) and above 1.0 M (second) GdnHCl. The changes in the first phase were slight but significant: decreases in ellipticity and light scattering, and an increase in E2 activity. Insignificant changes in the molecular shape and size of the core were detected on fluorescence spectroscopy, ultracentrifugation, gel filtration, and electron microscopy. On the other hand, the changes in the second phase were drastic; the core was disassembled and denatured.

Original languageEnglish
Pages (from-to)564-567
Number of pages4
JournalJournal of biochemistry
Issue number4
Publication statusPublished - Jan 1 1998
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology

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