Document 0021
 DOCN  M9610021
 TI    Purification and characterization of malate dehydrogenase from
       Cryptococcus neoformans.
 DT    9601
 AU    Mahmoud YA; el Souod SM; Niehaus WG; Department of Biochemistry and
       Anaerobic Microbiology, Virginia; Polytechnic Institute and State
       University, Blacksburg 24061,; USA.
 SO    Arch Biochem Biophys. 1995 Sep 10;322(1):69-75. Unique Identifier :
       AIDSLINE MED/96004781
 AB    The NAD-dependent malate dehydrogenase (EC 1.1.1.37) was purified from
       Cryptococcus neoformans, a basidiomycetious yeast that is an
       opportunistic pathogen of AIDS patients. The purified enzyme was a dimer
       of 35 kDa subunits that exhibited uncompetitive substrate inhibition by
       oxalacetate, typical for mitochondrial malate dehydrogenases from other
       sources. Product inhibition studies indicated an ordered sequential
       kinetic mechanism, with pyridine dinucleotide being the substrate that
       binds to the free enzyme form. Unique aspects of this malate
       dehydrogenase were inhibition by zinc ion, competitive versus malate
       with Ki of 30 microM, and inhibition by heparin. Heparin inhibition was
       competitive versus either NAD or malate, with Ki of 0.35 microM. Heparin
       molecules of nominal molecular weight of 30,000 or 3000 were equally
       effective inhibitors. A model is presented to explain the high affinity
       of the enzyme for heparin.
 DE    AIDS-Related Opportunistic Infections/DRUG THERAPY/MICROBIOLOGY  Binding
       Sites  Cryptococcosis/COMPLICATIONS/DRUG THERAPY/MICROBIOLOGY
       Cryptococcus neoformans/*ENZYMOLOGY/PATHOGENICITY  Drug Resistance,
       Microbial  Heparin/METABOLISM/PHARMACOLOGY  Human  Hydrogen-Ion
       Concentration  Kinetics  Malate Dehydrogenase/ANTAGONISTS &
       INHIB/CHEMISTRY/*ISOLATION &  PURIF  Molecular Weight  NAD/PHARMACOLOGY
       Oxaloacetates/PHARMACOLOGY  Protein Conformation  Support, Non-U.S.
       Gov't  Support, U.S. Gov't, P.H.S.  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).