Influence of Certain Cations on Activity of Succinyl CoA Synthetase From Tobacco

Abstract

A bstract. Succinyl CoA synthetase from Nicotiana tabacum exhibited a requirement for univalent and divalent cations. Mn2' replaced Mg2l in the assay medium and Co2' and Ca82 partially replaced Mg2+. Addition of Zn2' resulted in no enzyme activity. The enzvme was activated by univalent cations K+, Rb+, NH4+, and Na+; Li+ showed little or no activation. Maximum enzyme activity varied significantly with potassium salts of different anions.Greatest activation was obtained with K PO4 and, respectively, KCI, KNO1, K2SO4

Responses to K deficiency and waterlogging interact via respiratory and nitrogen metabolism

“…Second, low K conditions led to a typical accumulation of citramalate, which is one of the best biomarkers. Succinate thiokinase catalyzes a reversible reaction that has been shown to require K + for maximal activity (Besford & Maw, ; Bush, ), and without K + , the equilibrium favours much less the forward direction, that is, succinyl‐CoA conversion to succinate (Lynn & Guynn, ). In addition, pyruvate kinase is a well‐known K + ‐dependent enzyme, and low K + impedes pyruvate formation (Besford & Maw, ; Evans, ; Nowak & Mildvan, ).…”

“…However, it also reflects the fact that putrescine accumulation was suppressed by waterlogging, indicating a potential link between respiration and polyamines. In fact, putrescine synthesis produces CO 2 , and arginine synthesis (precursor of polyamines) requires NADPH (Slocum, 2005) (Besford & Maw, 1976;Bush, 1969), and without K + , the equilibrium favours much less the forward direction, that is, succinyl-CoA conversion to succinate (Lynn & Guynn, 1978). In addition, pyruvate kinase is a well-known K + -dependent enzyme, and low K + impedes pyruvate formation (Besford & Maw, 1976;Evans, 1963;Nowak & Mildvan, 1972).…”

Enzymes Activated by Monovalent Cations

“…Subclass where X is 0, NH, or CHs Rumen microorganism (33) Bacillus polymyxa (34), Rhodopseudomonas spheroides (35) Rat heart (35,36), rabbit heart (37) Streptococcus faecalis (38) Pigeon liver (39), Saccharomyces cerevisiae (40) Tobacco leaves (41) Phaseolus vulgaris (seedlings) (42), Triticum vulgare (wheat germ) (43) Escherichia coli (44) S. cerevisiae (45), rat liver (45) Human erythrocytes (46), chicken liver (46), leukocytes (47), Aerobacter aerogenes (48), spinach leaves (49) E. coli (50), rat liver (51) Bovine liver (52), pig heart (53) Rat liver (54), pancreas (55) E. coli (56) E. coli (57) Rabbit muscle (58), Amia colva (58) (enzyme in nine other marine organisms was activated by K+), Zea mays (seed) (59), Cucurbita pepo (seed) (60), rat brain (61), yeast (62), mouse liver (63) Aspergillus niger (65) Bacteroides symbiosus (66) Bovine liver (67) Rabbit muscle (68), yeast (69), sheep brain (70), rat brain (71), slime mold (72) Pigeon liver (73) reactions E. coli (74) Bacillus subtilis (75) Rat liver (76), E. coli (77) Sheep liver (76), yeast (78) Rhodopseudomonas spheroides (79) A. aerogenes (80) Clostridiuim …”

Properties and regulatory effect on tetrapyrrole biosynthesis of succinyl CoA synthetase isolated from soybean callus tissue system

“…It has been purified from mammalian, bacterial and plant tissues such as spinach [I] , wheat leaves [2] , artichoke mitochondria [3] and tobacco [4] .…”

“…Succinyl-CoA is involved in the early steps of the biosynthesis of tetrapyrrole compounds such a haem and chlorophyll and its formation is catalysed by sucnicyl-CoA synthetase (succinate: CoA ligase (GDP or ADP) EC 6.2.1.4 or 6.2.1.5). It has been purified from mammalian, bacterial and plant tissues such as spinach [I] , wheat leaves [2] , artichoke mitochondria [3] and tobacco [4] . This communication reports some properties of succinylCoA synthetase isolated and partially purified from soybean callus, a highly dividing tissue, useful for detecting active systems as was described by Miller [5] .…”