Reaction of Mycobacterium tuberculosis cytochrome P450 enzymes with nitric oxide.
Reaction of Mycobacterium tuberculosis cytochrome P450 enzymes with nitric oxide.
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DOI：
10.1021/bi801595t
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发表时间：
2009-02-10
期刊：
影响因子：
2.9
通讯作者：
Ortiz de Montellano PR
中科院分区：
文献类型：
--
作者：
Ouellet H;Lang J;Couture M;Ortiz de Montellano PR
在结核分枝杆菌（Mycobacterium tuberculosis，Mtb）感染的初期，宿主巨噬细胞产生的·NO抑制含血红素的末端细胞色素氧化酶，使铁硫蛋白失活，并促进进入潜伏期。在这里，我们评估了·NO作为Mtb细胞色素P450酶抑制剂的潜力，如CYP 130，CYP 51和两个以前未表征的酶CYP 125和CYP 142。利用紫外-可见吸收光谱、共振拉曼光谱和停流光谱，我们研究了·NO与这些铁静止形式的血红素蛋白的反应。·NO紧密地与CYP 125和CYP 142（亚微摩尔）配位，并且与CYP 130和CYP 51具有较低的亲和力（微摩尔）。厌氧还原的亚铁-NO物种与连二亚硫酸钠导致两个光谱上不同的类的五配位亚铁-NO配合物的形成。这些物种暴露于O2显示，CYP 125和CYP 142的亚铁-NO形式是不稳定的，并在几分钟内转化回铁态，而亚铁CYP 130和CYP 51几乎不可逆地结合·NO。这项工作清楚地表明，在生理浓度（101 μM）下，·NO会损害CYP 130和CYP 51的活性，而CYP 125和CYP 142更具抗性。选择性抑制P450可能与NO抑制结核分枝杆菌生长有关。
During the initial growth infection stage of Mycobacterium tuberculosis (Mtb), •NO produced by host macrophages inhibits heme-containing terminal cytochrome oxidases, inactivates iron/sulfur proteins and promotes entry into latency. Here we evaluate the potential of •NO as an inhibitor of Mtb cytochrome P450 enzymes, as represented by CYP130, CYP51 and the two previously uncharacterized enzymes CYP125 and CYP142. Using UV-visible absorption, resonance Raman, and stopped-flow spectroscopy, we investigated the reactions of •NO with these hemeproteins in their ferric resting form. •NO coordinates tightly to CYP125 and CYP142 (submicromolar), and with a lower affinity (micromolar) to CYP130 and CYP51. Anaerobic reduction of the ferric-NO species with sodium dithionite led to the formation of two spectrally distinct classes of five-coordinate ferrous-NO complexes. Exposure of these species to O2 revealed that the ferrous-NO forms of CYP125 and CYP142 are labile and convert back to the ferric state within a few minutes, whereas ferrous CYP130 and CYP51 bind •NO almost irreversibly. This work clearly indicates that, at physiological concentrations (≈ 1 μM), •NO would impair the activity of CYP130 and CYP51, whereas CYP125 and CYP142 are more resistant. Selective P450 inhibition may contribute to the inhibitory effects of •NO on Mtb growth.
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影响因子：
15
作者：
HU, SZ;KINCAID, JR
通讯作者：
KINCAID, JR
DOI：
10.1016/s0962-8479(97)90004-6
发表时间：
1997-01-01
期刊：
TUBERCLE AND LUNG DISEASE
影响因子：
--
作者：
Adams, LB;Dinauer, MC;Krahenbuhl, JL
通讯作者：
Krahenbuhl, JL
DOI：
10.1073/pnas.96.16.8937
发表时间：
1999-08-03
影响因子：
11.1
作者：
Bellamine, A;Mangla, AT;Waterman, MR
通讯作者：
Waterman, MR
影响因子：
4.8
作者：
Couture, M;Burmester, T;Rousseau, DL
通讯作者：
Rousseau, DL
DOI：
10.1165/ajrcmb.25.5.4487
发表时间：
2001-11-01
影响因子：
6.4
作者：
Chan, ED;Chan, J;Schluger, NW
通讯作者：
Schluger, NW