Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Enzymatic degradation of cyclic 2,3-diphosphoglycerate to 2,3-diphosphoglycerate in Methanobacterium thermoautotrophicum

Journal Article · · Biochemistry; (United States)
DOI:https://doi.org/10.1021/bi00126a012· OSTI ID:5640111

2,3-Diphosphoglycerate (2,3-DPG) has been found to be the product of the enzymatic degradation of cyclic 2,3-diphosphoglycerate (cDPG) in the archaebacterium Methanobacterium thermoautotrophicum {Delta}H. Although 2,3-DPG has not previously been detected as a major soluble component of M. thermoautotrophicum, large pools accumulated at an incubation temperature of 50C. Under these conditions, cellular activity was significantly decreased; a return of the culture to the optimum growth temperature restored the 2,3-DPG pool back to original low levels and caused steady-state cDPG levels to increase again. While {sup 13}CO{sub 2}-pulse/{sup 12}CO{sub 2}-chase experiments at 50C showed that the cDPG turned over, the appearance of 2,3-DPG at NMR-visible concentrations required at least 10 h. Production of 2,3-DPG in vivo was prevented by exposure of the cells to O{sub 2}. the enzyme responsible for this hydrolysis of cDPG was purified by affinity chromatography and appears to be a 33-kDa protein. Activity was detected in the presence of oxygen and was enhanced by a solution of 1 M KCl, 25 mM MgCl{sub 2}, and dithiothreitol. Both K{sub m} and V{sub max} have been determined at 37C; kinetics also indicate that in vitro the product, 2,3-DPG, is an inhibitor of cDPG hydrolysis. These findings are discussed in view of a proposed role for cDPG in methanogens.

DOE Contract Number:
FG02-91ER20025
OSTI ID:
5640111
Journal Information:
Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 31:11; ISSN 0006-2960; ISSN BICHA
Country of Publication:
United States
Language:
English