title: Characterization of an inhibitor of ribonucleic acid polymerase from the mycelial phase of Histoplasma capsulatum.
abstract: An inhibitor of ribonucleic acid polymerases has been obtained from the mycelial phase of Histoplasma capsulatum and partially characterized. The inhibitor, called histin, was purified 200-fold by heat treatment at 100 C and electrophoresis on polyacrylamide gels. Histin moved in electrophoresis as if negatively charged; it was insensitive to treatment with ribonuclease of deoxyribonuclease but was completely digested by Pronase. Sucrose gradient centrifugation suggests a molecular weight of 24,000. The possibility of a regulatory role for histin in the life cycle of H. capsulatum is discussed.
mesh_terms: D002474:Cell-Free System; D002499:Centrifugation, Density Gradient; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors; D003851:Deoxyribonucleases / Q000378:metabolism; D004589:Electrophoresis, Disc; D004791:Enzyme Inhibitors / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D005656:Fungal Proteins / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D006658:Histoplasma / Q000032:analysis* / Q000201:enzymology / Q000254:growth & development; D006358:Hot Temperature; D008970:Molecular Weight; D011402:Pronase / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D012321:DNA-Directed RNA Polymerases; D003851:Deoxyribonucleases; D012260:Ribonucleases; D011402:Pronase