ANTI-BACTERIAL PEPTIDE FROM NORMAL RABBIT SERUM .3. INHIBITION OF MICROBIAL ELECTRON-TRANSPORT
ANTI-BACTERIAL PEPTIDE FROM NORMAL RABBIT SERUM .3. INHIBITION OF MICROBIAL ELECTRON-TRANSPORT
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DOI：
10.1021/bi00524a010
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发表时间：
1981-01-01
期刊：
影响因子：
2.9
通讯作者：
MARTINEZ, RJ
中科院分区：
文献类型：
--
作者：
CARROLL, SF;MARTINEZ, RJ
研究了主要兔血清杀菌剂PC-III对枯草芽孢杆菌呼吸活性的影响。全细胞依赖葡萄糖或乳酸的呼吸被产生显著细胞死亡的杀菌剂浓度迅速而完全地抑制。膜小泡氧化NADH也有类似的结果。在这两种情况下，杀菌剂对呼吸的抑制都是钙依赖的，并阻断了细胞色素b和a之间的电子传递。PC-Ⅲ与氧化酵母细胞色素c竞争，后者作为电子受体参与枯草杆菌膜囊泡催化的细胞色素c还原反应。以还原酵母菌细胞色素c为电子供体时，PC-Ⅲ对细胞色素c氧化酶也有竞争性抑制作用。在离子强度为0.13时，PC-III对还原酶和氧化物络合物的KI分别为25.9和102 nm。将离子强度增加到对整个细胞产生最佳抗菌作用的离子强度(0.24)时，PC-III对还原酶的KI增加(75.4 nM)，而对氧化酶的KI降低(92.3 nM)。
The influence of the primary rabbit serum bactericide, PC-III, on the respiratory activity of Bacillus subtilis was examined. Glucose- or lactate-dependent respiration by whole cells was rapidly and completely inhibited by concentrations of the bactericide producing significant cell death. Similar results were observed with membrane vesicles oxidizing NADH. In both cases, bactericide-induced inhibition of respiration was Ca dependent and blocked electron transport between cytochromes b and a. PC-III competed with oxidized Saccharomyces cytochrome c when the latter was used as an electron acceptor in cytochrome c reductase reactions catalyzed by B. subtilis membrane vesicles. Competitive inhibition by PC-III was also observed when reduced Saccharomyces cytochrome c was used as electron donor in the cytochrome c oxidase reaction. At an ionic strength of 0.13, PC-III exhibits a ki of 25.9 and 102 nM for the reductase and oxidase complexes, respectively. Increasing the ionic strength to that producing optimal antibacterial action against whole cells (0.24) increased the ki of PC-III for the reductase (75.4 nM), while that for the oxidase decreased (92.3 nM).