Active Site Structural Features for Chemically Modified Forms of Rhodanese

Active site structural features for chemically modified forms of rhodanese.

In the course of the reaction catalyzed by rhodanese, the enzyme cycles between two catalytic intermediates, the sulfur-free and the sulfur-substituted (persulfide-containing) forms. The crystal structure of sulfur-free rhodanese, which was prepared in solution and then crystallized, is highly similar to that of sulfur-substituted enzyme. The inactivation of sulfur-free rhodanese with a small m...

PROBING THE ACTIVE SITE OF RHODANESE WITH DISULFIDE REAGENTS

Studies on the active site of rhodanese.

The complete loss of enzymic activity on reaction with alkylating agents, aromatic nitro compounds, or aliphatic mercaptans indicates the importance of sulfhydryl groups for catalysis. Analyses during the course of inactivation with any of these reagents revealed the loss of one of the two -SH groups in the rhodanese monomer when inactivation was complete. Amino acid analysis of iodoacetate-ina...

probing the active site of rhodanese with disulfide reagents

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Structural studies of bovine liver rhodanese. I. Isolation and characterization of two active forms of the enzyme.

Crystalline bovine liver rhodanese, prepared by ammonium sulfate and pH precipitation, has been shown to be comprised of two fully active components present in approximately equal amounts which are separable by polyacrylamide gel electrophoresis and by ion exchange chromatography. The two rhodanese forms, designated A and B on the basis of their order of elution from columns of DEAE-Sephadex, a...