Potuznik S, Gelvan D, Burda P, Saltman P
Department of Biology, University of California, San Diego, La Jolla.
Biochim Biophys Acta. 1993 Aug 7;1164(3):289-98. doi: 10.1016/0167-4838(93)90261-o.
The beta subunit of human hemoglobin can be oxidized site-specifically through beta-Cys-93 by Cu(II)(His)2. A series of thiol ligands, gold thiols and zinc(II) inhibit this oxidation. The thiol inhibitors formed a transient ternary intermediate involving Cu(I) with consequent inhibition of electron transfer from the Fe(II)-heme. The intermediate led to the formation of a disulfide at the beta-Cys-93 site. The most effective thiols achieved maximum inhibition at one equivalent per beta heme. Gold thiols and zinc complexes inhibited heme oxidation by competing with the Cu(II)(His)2 for the beta-Cys-93 site.
人血红蛋白的β亚基可通过β-半胱氨酸-93被Cu(II)(His)2位点特异性氧化。一系列硫醇配体、金硫醇和锌(II)可抑制这种氧化。硫醇抑制剂形成了一种涉及Cu(I)的瞬态三元中间体，从而抑制了电子从Fe(II)-血红素的转移。该中间体导致在β-半胱氨酸-93位点形成二硫键。最有效的硫醇在每个β血红素一个当量时达到最大抑制效果。金硫醇和锌配合物通过与Cu(II)(His)2竞争β-半胱氨酸-93位点来抑制血红素氧化。
