Fatty acid-induced alteration of the porphyrin macrocycle of cytochrome P450 BM3
Fatty acid-induced alteration of the porphyrin macrocycle of cytochrome P450 BM3
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DOI：
10.1016/s0006-3495(98)78030-0
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发表时间：
1998-06-01
影响因子：
3.4
通讯作者：
Smith, WE
中科院分区：
文献类型：
--
作者：
Macdonald, IDG;Munro, AW;Smith, WE
报道并归属了细胞色素P450 BM3的P450结构域的无底物和底物结合形式的表面增强共振拉曼散射(SERRS)。无底物P450产生混合自旋血红素物种，其中五坐标高自旋排列占主导地位。月桂酸酯或棕榈酸酯的加入导致高自旋含量增加，并导致血红素模式v(29)的变构激活，该模式对外周血红素/蛋白质相互作用敏感。月桂酸酯和棕榈酸酯结合在一些带的相对强度和血红素乙烯基模式的分裂方面有差异。月桂酸与P450的结合导致每种乙烯基模式经历的蛋白质环境不同，而棕榈酸结合产生的差异较小。结果表明，在低蛋白质浓度下，SERRS能够探测活性部位内的底物/修复基团相互作用。
Surface-enhanced resonance Raman scattering (SERRS) of substrate-free and substrate-bound forms of the P450 domain of cytochrome P450 BM3 are reported and assigned. Substrate-free P450 yields mixed spin heme species in which the pentacoordinate high-spin arrangement is dominant. The addition of laurate or palmitate leads to an increase in high spin content and to an allosteric activation of heme mode v(29), which is sensitive to peripheral heme/protein interactions. Differences between laurate and palmitate binding are observed in the relative intensities of a number of bands and the splitting of the heme vinyl modes. Laurate binding to P450 results in different protein environments being experienced by each vinyl mode, whereas palmitate binding produces a smaller difference. The results demonstrate the ability of SERRS to probe substrate/prosthetic group interactions within an active site, at low protein concentrations.