title: Cleavage of phosphorylase kinase and calcium-free calmodulin by HIV-1 protease.
abstract: Phosphorylase kinase and calcium-free calmodulin are digested by human immunodeficiency virus-1 protease. In phosphorylase kinase, the alpha subunit is preferentially hydrolyzed at arg748-val749. The beta subunit is cleaved only slowly at leu678-pro679, and calmodulin, the integral delta subunit of phosphorylase kinase, is not cleaved at all. However, free calmodulin in the calcium-depleted form showed to be a good substrate for the protease. Here the cleavage occurs at phe65-pro66 and met71-met72. This fast hydrolysis of free calmodulin can be blocked by micromolar concentrations of Ca2+ or millimolar concentrations of Mg2+.
authors.affiliation: Max-Planck-Institut für Biochemie, Martinsried bei München, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Daube
authors.forename: A
authors.initials: A
authors.lastname: Billich
authors.forename: K
authors.initials: K
authors.lastname: Mann
authors.forename: H J
authors.initials: HJ
authors.lastname: Schramm
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002122:Calcium Chloride / Q000494:pharmacology; D002147:Calmodulin / Q000378:metabolism*; D003198:Computer Simulation; D016333:HIV Protease / Q000378:metabolism*; D015497:HIV-1 / Q000201:enzymology*; D007700:Kinetics; D046911:Macromolecular Substances; D015636:Magnesium Chloride / Q000494:pharmacology; D008958:Models, Molecular; D009132:Muscles / Q000201:enzymology; D010764:Phosphorylase Kinase / Q000378:metabolism*; D011487:Protein Conformation; D011817:Rabbits; D011994:Recombinant Proteins / Q000378:metabolism; D013379:Substrate Specificity; D014961:X-Ray Diffraction
chemical_list: D002147:Calmodulin; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D015636:Magnesium Chloride; D010764:Phosphorylase Kinase; D016333:HIV Protease; D002122:Calcium Chloride