OXIDATION AND TRANSAMINATION OF GLUTAMATE BY TYPHUS RICKETTSIAE

Abstract

It has been previously reported (1) that partially purified rickettsiae are capable of oxidizing glutamate and that the rate of this reaction is proportional to the number of viable organisms present.It seemed of considerable interest to extend these observations in an effort to obtain more detailed information concerning the nature of the reactions involved, and to search for other reactions which these obligate intracellular organisms might catalyze.Although this work has been somewhat hampered by the difficulty in obtaining sufficient quantities of rickettsiae for analytical work, it has been possible to determine some of the end-products of glutamate oxidation and to establish the occurrence of a rickettsial transaminase. Methods Solutions-Forthe sake of brevity, the composition of the solutions used in preparation of the rickettsiae is listed below and these will subsequently be referred to by the designated abbreviation.K-r&KC4 0.118 M; NaCl, 0.0072 M; Na2HP04, 0.0076 M; KHpP04, 0.0040 M; potassium glutamate, 0.0042 M; pH 7.0.K-7.6-KCl, 0.126 M; NaCl, 0.0018 M; N&HPO+ 0.0106 M; KH~POI, 0.0012 M; pH 7.6.KN--KCl, 0.122 M; NaCl, 0.023 M. KN-G-100 ml.solution of KN + 3.0 ml. of 0.168 M potassium glutamate, pH 7.0.Sucrose-P-Sucrose, 0.225 M; KHzP04, 0.0016 M; KtHPOa, 0.0086 M, pH 7.5.!&is-7.6-100 ml. of 0.3 M trishydroxymethylaminomethane + 75 ml. of 0.3 M HCl, pH 7.5.Sucrose-his90 ml. of 0.25 M sucrose + 10 ml. of tris-7.5.6 per cent albumin-A solution of either bovine or human serum albumin.