Purification and characterization of monomeric isocitrate dehydrogenase with NADP(+)-specificity from Vibrio parahaemolyticus Y-4.
NADP(+)-dependent isocitrate dehydrogenase [IDH: EC 1.1.1.42] was purified to electrophoretic homogeneity from Vibrio parahaemolyticus Y-4, and shown to be a monomeric protein of molecular weight 80,000 with a pI of 5.0. The amino acid composition and partial sequence at the N-terminus resembled those reported for other bacterial monomeric IDHs. Immunotitration with antisera to the monomeric and dimeric enzymes (antisera to IDH-II and -I of Vibrio ABE-1) showed an immunochemical distinction between the monomeric and dimeric IDHs, but there is similarity within the IDHs of each group. The circular dichroism spectra of the native and heat-denatured enzyme are also similar to those of monomeric IDH (IDH-II of Vibrio ABE-1). These monomeric IDHs are proteins comprising 17-22% helix and 25-35% beta-pleated sheet in the native state.
Fukunaga
N
N
Department of Biology, Faculty of Science, Hokkaido University.
Imagawa
S
S
Sahara
T
T
Ishii
A
A
Suzuki
M
M
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001419:Bacteria / Q000201:enzymology; D002852:Chromatography, Ion Exchange; D002942:Circular Dichroism; D004795:Enzyme Stability; D007521:Isocitrate Dehydrogenase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009249:NADP / Q000378:metabolism*; D011487:Protein Conformation; D011489:Protein Denaturation; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013816:Thermodynamics; D014736:Vibrio parahaemolyticus / Q000201:enzymology*
D000596:Amino Acids; D009249:NADP; D007521:Isocitrate Dehydrogenase