Adduct Formation between the Cupric Site of Phenylalanine Hydroxylase from Chromobacterium violaceum and 6,7-Dimethyltetrahydropterin

Stephen O. Pember, Stephen J. Benkovic, Joseph J. Villafranca, Marta Pasenkiewicz-Gierula, William E. Antholine

Research output: Contribution to journalArticlepeer-review

27 Scopus citations

Abstract

The interaction of pterin-dependent phenylalanine hydroxylase from Chromobacterium violaceum with the cofactor analogue 5-deaza-6-methyltetrahydropterin and the cofactor 6,7-dimethyltetrahydropterin (DMPH4) has been investigated by multifrequency electron spin resonance (ESR) spectroscopy. 5-Deaza-6-methyltetrahydropterin, which lacks the N-5 nitrogen present in the pyrazine ring of DMPH4, binds tightly to the cupric form of the enzyme; however, no changes are observed in the ESR parameters of the copper center. In contrast, the binding of DMPH4 (or 6-methyltetrahydropterin) shifts the ESR parameters and Ay) associated with the cupric enzyme. In addition, superhyperfine transitions were resolved and assigned to hyperfine splitting from nitrogen ligands. ESR spectra of the enzyme recorded in the presence of [5-14N]DMPH4 or [5-15N]DMPH4 were computer simulated and found to be consistent with pterin serving as a direct donor ligand to the copper center through the N-5 position.

Original languageEnglish (US)
Pages (from-to)4477-4483
Number of pages7
JournalBiochemistry
Volume26
Issue number14
DOIs
StatePublished - 1987

All Science Journal Classification (ASJC) codes

  • Biochemistry

Fingerprint Dive into the research topics of 'Adduct Formation between the Cupric Site of Phenylalanine Hydroxylase from Chromobacterium violaceum and 6,7-Dimethyltetrahydropterin'. Together they form a unique fingerprint.

Cite this