Phospholipid catabolism enzymes of leptospires.

Phospholipase A2, C, D activities of pathogenic (VGNCI-3, HS-26) and saprophytic (K-1028, G-80) strains of leptospires were determined. The strains used synthesized intracellular and extracellular forms of these esterases. To a considerable degree the endophospholipase activity was associated with the membrane structures. Differences in substrate specificity, Km, Vmax pH optimum values between exophospholipases of pathogenic and saprophytic leptospires used in the experiments are demonstrated.

[Electrophoretic study of the outer membrane proteins of leptospirae]. / Elektroforeticheskoe issledovanie belkov naruzhnoi obolochki leptospir.

The outer membranes of pathogenic and saprophytic leptospires have been isolated. The spectrum of outer membrane proteins in three saprophytic and one pathogenic Leptospira strains has been studied by means of electrophoresis in polyacrylamide gel. In Leptospira strains VGNKI-6 (pathogenic) and G-80 (saprophytic) identical proteins, as well as proteins similar in their Rf value, have been detected. The possibility of using strain G-80 for the development of leptospiral vaccine against serovars having common surface antigens with this strain has been suggested.

Fatty acids as resource of carbon for leptospirae.

The effect of saturated (palmitic, stearic, myristic) and unsaturated (oleic) fatty acids on the proliferation of Leptospirae was studied. Proliferation of the saprophytic strains G-45, K-1028 (serovar not identified) and of the pathogenic strain VGNKI-3 (serovar canicola) of Leptospirae was obtained on a serum-free medium with the addition of saturated fatty acids. The unsaturated oleic acid at relatively high concentrations (0.5 mg/ml) suppresses proliferation of these spirochetes. It has been demonstrated that the variants used in the experiment can be utilized for the study of nutritional requirements of Leptospirae and their metabolism.