Direct evidence of conformational heterogeneity in human pancreatic glucokinase from high-resolution nuclear magnetic resonance.

ABSTRACT: High-resolution nuclear magnetic resonance is used to investigate the conformational dynamics of human glucokinase, a 52 kDa monomeric enzyme that displays kinetic cooperativity. (1)H-(15)N transverse relaxation optimized spectra of uniformly labeled glucokinase, recorded in the absence and presence of glucose, reveal significant cross-peak overlap and heterogeneous peak intensities that persist over a range of temperatures. (15)N-specific labeling of isoleucines and tryptophans, reporting on backbone and side chain dynamics, respectively, demonstrates that both unliganded and glucose-bound enzymes sample multiple conformations, although glucose stabilizes certain conformations. These results provide the first direct evidence of glucokinase conformational heterogeneity and hence shed light

SUBMITTER: Larion M 

PROVIDER: S-EPMC3023983 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature