Aue B J, Deiel R H
J Bacteriol. 1967 Jun;93(6):1770-6. doi: 10.1128/jb.93.6.1770-1776.1967.
Some characteristics of a fumarate reductase from Streptococcus faecalis are described. The enzyme had a pH optimum of 7.4; optimal activity was observed when the ionic strength of the phosphate buffer was adjusted to 0.088. The K(m) value of the enzyme for reduced flavin mononucleotide was 2 x 10(-4)m as determined with a 26-fold preparation. In addition to fumarate, the enzyme reduced maleate and mesaconate. No succinate dehydrogenase activity was detected, but succinate did act as an inhibitor of the fumarate reductase activity. Other inhibitors were malonate, citraconate, and trans-, trans-muconate. Metal-chelating agents did not inhibit the enzyme. A limited inhibition by sulfhydryl-binding agents was observed, and the preparations were sensitive to air oxidation and storage. Glycine, alanine, histidine, and possibly lysine stimulated fumarate reductase activity in the cell-free extracts. However, growth in media supplemented with glycine did not enhance fumarate reductase activity. The enzymatic activity appears to be constitutive.
本文描述了粪肠球菌中富马酸还原酶的一些特性。该酶的最适pH值为7.4；当磷酸盐缓冲液的离子强度调至0.088时，可观察到最佳活性。用26倍浓缩制剂测定，该酶对还原型黄素单核苷酸的K(m)值为2×10(-4)m。除富马酸外，该酶还能还原马来酸和中康酸。未检测到琥珀酸脱氢酶活性，但琥珀酸确实可作为富马酸还原酶活性的抑制剂。其他抑制剂还有丙二酸、柠康酸和反式、反式粘康酸。金属螯合剂不抑制该酶。观察到巯基结合剂有一定程度的抑制作用，且制剂对空气氧化和储存敏感。甘氨酸、丙氨酸、组氨酸以及可能的赖氨酸可刺激无细胞提取物中的富马酸还原酶活性。然而，在添加甘氨酸的培养基中生长并未增强富马酸还原酶活性。该酶活性似乎是组成型的。
