Investigations of low-frequency vibrational dynamics and ligand binding kinetics of cystathionine beta-synthase.

ABSTRACT: Vibrational coherence spectroscopy is used to study the low frequency dynamics of the truncated dimer of human cystathionine beta-synthase (CBS). CBS is a pyridoxal-5'-phosphate-dependent heme enzyme with cysteine and histidine axial ligands that catalyzes the condensation of serine and homocysteine to form cystathionine. A strong correlation between the "detuned" coherence spectrum (which probes higher frequencies) and the Raman spectrum is demonstrated, and a rich pattern of modes below 200 cm(-1) is revealed. Normal coordinate structural decomposition (NSD) of the ferric CBS crystal structure predicts the enhancement of normal modes with significant heme "doming", "ruffling", and "saddling" content, and they are observed in the coherence spectra near approximately 40, approximately 60,

SUBMITTER: Karunakaran V 

PROVIDER: S-EPMC2842918 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature