Kula T J, Aleem M I, Wilson D F
Biochim Biophys Acta. 1982 May 19;680(2):142-51. doi: 10.1016/0005-2728(82)90005-6.
(1) Cells of Thiobacillus A2 grown chemoautotrophically on thiosulfate or heterotrophically on succinate with oxygen contained b-, c-, o-, a- and a3-type cytochromes. The amount of cytochrome per mg of cell protein was much greater in thiosulfate-grown cells and differences in the relative concentrations of cytochromes were observed for the different growth conditions. (2) The half-reduction potentials at pH 7.0 (Em,7.0) and spectral maxima of c-, b-, a- and a3-type cytochromes were similar in cells grown aerobically with thiosulfate or with succinate as the growth substrate. (3) The half-reduction potential of the 'invisible', or high-potential copper, as determined from the potentiometric behavior of the carbon monoxide-reduced cytochrome a3 complex at pH 8.0, was 365 mV. (4) Reducing equivalents from thiosulfate appear to enter the respiratory chain at the cytochrome c level; however, studies in cell-free extracts were limited due to a loss in respiratory activity with thiosulfate as a substrate upon cell disruption.
(1) 在硫代硫酸盐上进行化能自养生长或在琥珀酸盐上进行异养生长且有氧存在时，嗜硫杆菌A2的细胞含有b型、c型、o型、a型和a3型细胞色素。每毫克细胞蛋白中细胞色素的含量在硫代硫酸盐生长的细胞中要多得多，并且在不同生长条件下观察到细胞色素相对浓度的差异。(2) 以硫代硫酸盐或琥珀酸盐作为生长底物进行好氧生长的细胞中，c型、b型、a型和a3型细胞色素在pH 7.0时的半还原电位（Em,7.0）和光谱最大值相似。(3) 根据pH 8.0时一氧化碳还原的细胞色素a3复合物的电位行为测定，“不可见”或高电位铜的半还原电位为365 mV。(4) 来自硫代硫酸盐的还原当量似乎在细胞色素c水平进入呼吸链；然而，由于细胞破碎后以硫代硫酸盐作为底物时呼吸活性丧失，无细胞提取物的研究受到限制。
