Intracellular Localization of Enzymes in Mycobacterium tuberculosis var Hominis.

Abstract

By grinding cells of M. tuberculosis var. hominis H37Ra using a ball mill and by differential centrifugation in a Spinco Ultra-centrifuge Model L, 4 particulate fractions and 1 supernatant fraction were obtained. The particulate fractions contained units from 19 to 200[mu] in diameter. Quantitative localization studies showed that aconitase, catalase, fumarase, a-keto-glutaric dehydrogenase, isocitric dehydrogenase and malic dehydrogenase were located almost entirely in the supernatant fraction, while cytochrome oxidase, DPNH oxidase and succinic dehydrogenase were found to be associated mainly with the two largest particulate fractions. Of the 4 only the 2 largest particulate fractions contain a complete cytochrome system and are equivalent in this respect to mitochondria of higher forms.