title: New aspartic proteinase of Ulysses retrotransposon from Drosophila virilis.
abstract: This work is focused on the investigation of a proteinase of Ulysses mobile genetic element from Drosophila virilis. The primary structure of this proteinase is suggested based on comparative analysis of amino acid sequences of aspartic proteinases from retroviruses and retrotransposons. The corresponding cDNA fragment has been cloned and expressed in E. coli. The protein accumulated in inclusion bodies. The recombinant protein (12 kD) was subjected to refolding and purified by affinity chromatography on pepstatin-agarose. Proteolytic activity of the protein was determined using oligopeptide substrates melittin and insulin B-chain. It was found that the maximum of the proteolytic activity is displayed at pH 5.5 as for the majority of aspartic proteinases. We observed that hydrolysis of B-chain of insulin was totally inhibited by pepstatin A in the micromolar concentration range. The molecular weight of the monomer of the Ulysses proteinase was determined by MALDI-TOF mass-spectrometry.
authors.affiliation: Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117871, Russia. den@enzyme.siobc.ras.ru
authors.forename: D A
authors.initials: DA
authors.lastname: Volkov
authors.forename: N I
authors.initials: NI
authors.lastname: Dergousova
authors.forename: L D
authors.initials: LD
authors.lastname: Rumsh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D004330:Drosophila / Q000201:enzymology* / Q000235:genetics*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D018626:Retroelements / Q000235:genetics*
chemical_list: D029721:Drosophila Proteins; D011994:Recombinant Proteins; D018626:Retroelements; D016282:Aspartic Acid Endopeptidases; C475490:Ulysses retrotransposon aspartic proteinase, Drosophila