[Candida albicans].

Candida albicans is an opportunistic pathogen. Its proliferation in human hosts is believed to be controlled by immunologic mechanisms. The plasma membrane of the fungus posseses an H+-ATPase (PM-ATPase) which actively extrudes protons to generate an electrochemical gradient which is used in co-transport of nutrients. This ATPase is associated with the growth, dimorphism and pathogenicity of the fungu s. The physiological concentration of phosphocreatine (PCr) is 20-35 mM in skeletal muscles. H+-extrusion in Candida cells was strongly inhibited by PCr; 44% at 20mM and 69% at 40mM. W extrusion was stimulated 6.2-fold in the presence of I OmM glucose. This glucose stimulated extrusion was inhibited significantly by PCr; 36% at 20mM and 53% at 40mM. The intracellular pH pattern of cells destined to differentiate was greatly altered in the presence of PCr. Evagination time for control cells was between 90-120 min. PCr, delayed dimorphism, reduced the population of cells differentiating to hyphae and also reduced the length of hyphae a fter each time interval. Only 60% differentiation was observed with 10mM PCr and 40% for higher PCr concentration even after 210 min. Direct interaction of PM-ATPase and PCr has been demonstrated by difference spectrum measurement employing stopped flow spectrophotometer. It can be concluded that PCr may be playing a significant role in checking growth and pathogenesis of C. albicans.