1H NMR spectroscopy of the binuclear Cu(II) active site of Streptomyces antibioticus tyrosinase

FEBS Letters

Salgado, Jesús¹  Vijgenboom, Erik¹  Canters, Gerard W.¹  Tepper, Armand W.J.W.¹  Bubacco, Luigi¹ 

[1] Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands

关键词: Paramagnetic;    Phenoloxidase;    Oxygenase;    Exchange;    Copper protein;    Curie;   

DOI  :  10.1016/S0014-5793(98)01662-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The 600 MHz ¹H NMR spectrum of tyrosinase (31 kDa) of Streptomyces antibioticus in the oxidized, chloride-bound form is reported. The downfield part of the spectrum (15–55 ppm) exhibits a large number of paramagnetically shifted signals. The paramagnetism is ascribed to a thermally populated triplet state. The signals derive from six histidines binding to the metals through their Nϵ atoms. There is no evidence for endogenous bridges. The exchange coupling, −2J, amounts to 298 cm⁻¹. In the absence of chloride the peaks broaden. This is ascribed to a slowing down of the electronic relaxation. The exchange coupling decreases to −2J=103 cm⁻¹.

【 授权许可】

Unknown