1H NMR spectroscopy of cytochrome cd1 derivatives.
1H NMR spectroscopy of cytochrome cd1 derivatives.
复制标题
细胞色素 cd1 衍生物的 1H NMR 光谱。
DOI：
10.1016/0003-9861(85)90077-3
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发表时间：
1985
影响因子：
3.9
通讯作者：
Taylor,PV
中科院分区：
文献类型：
--
作者：
Timkovich,R;Cork,MS;Taylor,PV
Proton nuclear magnetic resonance spectra are reported for cytochromecd1fromPseudomonas aeruginosa(ATCC 19429) in several forms including complexes of the ferricytochrome with cyanide, azide, and fluoride, a quasi-apo form in which the noncovalently associated heme d1has been removed but the covalently bound heme c is retained, and the reduced state of both native and the quasi-apo forms. Comparisons are made to the previously reported spectrum of ferricytochromecd1. The following points are made. (i) The spectra of the azide and fluoride complexes and the ferric quasi-apo form show perturbation of resonances assignable to the site of heme d1, and leave relatively unperturbed resonances assignable to the site of heme c. The heme d1associated resonances are at 46.0, 35.4, 23.3, 17.5, −2.9, and −16 ppm, and the heme c associated resonances are at 42.0, 33.7, 15.0, 13.9, −7.5, −14, and −33 ppm in native ferricytochromecd1. (ii) The similarity of the hyperfine resonances of the ferric quasi-apo form to the heme c resonances of intact ferricytochromecd1is evidence that removal of heme d1leaves the heme c binding site relatively unaltered. (iii) Linewidths and relaxation times suggest that the relaxation times of the unpaired electron spins of the ferric hemes c and d1are on the same order of magnitude. (iv) Although it is paramagnetic, ferrocytochromecd1does not demonstrate an experimentally detectable hyperfine shifted spectrum under present conditions. Possible reasons for this are discussed. (v) The presence of a narrow resonance at −2.8 ppm in both ferrocytochromecd1and the reduced state of the quasi-apo form suggests that methionine may be a ligand to heme c.
