These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The enzymatic activity of phosphoglycerate mutase from gram-positive endospore-forming bacteria requires Mn2+ and is pH sensitive.
    Author: Chander M, Setlow B, Setlow P.
    Journal: Can J Microbiol; 1998 Aug; 44(8):759-67. PubMed ID: 9830105.
    Abstract:
    The enzymatic activity of phosphoglycerate mutase (Pgm) from three gram-positive endospore-forming bacteria (Bacillus subtilis, Clostridium perfringens, and Sporosarcina ureae) requires Mn2+ and is very sensitive to pH; at low concentrations of Mn2+, a pH change from 8 to 6 resulted in greater than 30- to 200-fold decreases in the activity of these Pgms. However, Pgm deactivation at pH 6 was reversed by shifting the enzyme to pH 7 or 8. Free Mn2+ was not directly involved in Pgm catalysis, although enzyme-bound Mn2+ may be involved. The rate of catalysis by Mn(2+)-containing Pgm was also slightly pH dependent, although the Km for 3-phosphoglyceric acid appeared to be the same at pH 6, 7, and 8. These findings suggest that Mn2+ binds to catalytically inactive Pgm and converts it to a catalytically competent form, and further, that pH influences the efficiency with which the enzyme binds Mn2+. The extreme pH sensitivity of the Mn(2+)-dependent Pgms supports a model in which this enzyme is inhibited during sporulation by acidification of the forespore, thus allowing accumulation of the spore's large depot of 3-phosphoglyceric acid. The activity of Pgm from two closely related gram-positive bacteria that do not form spores (Planococcus citreus and Staphylococcus saprophyticus) also requires Mn2+ and is pH sensitive. In contrast, the Pgm activities from two more distantly related non-endospore-forming gram-positive bacteria (Micrococcus luteus and Streptomyces coelicolor) are neither dependent on metal ions nor particularly sensitive to pH.
    [Abstract] [Full Text] [Related] [New Search]