title: Cleavage specificity on synthetic peptide substrates of human rhinovirus 2 proteinase 2A.
abstract: Proteinase 2A of human rhinovirus serotype 2 (HRV2 2A) was expressed in Escherichia coli and partially purified; the preparation was used to study various enzymatic parameters. Using a 16-amino acid peptide representing the native cleavage region of HRV2 2A, an apparent Km value of 5.4 x 10(-4) mol/liter was determined. A minimum of 9 amino acids (comprising residues P8 to P1') was necessary for cleavage to occur. Proteolysis of substituted peptides was highly tolerant toward changes at P1, P2', and P3' but an absolute requirement for glycine P1' and a high preference for threonine P2 was found. Furthermore, HRV2 2A only cleaved peptide substrates derived from other rhinovirus serotypes and poliovirus that possessed P2 Thr and P1' Gly. Thus, the sequence Thr-X-Gly may form the basis of the cellular cleavage site processed by rhinoviral 2As during viral replication. Studies with various inhibitors support the hypothesis that HRV2 2A belongs to a new class of cysteine proteinases.
authors.affiliation: Ernst Boehringer Institut fuer Arzneimittelforschung, Vienna, Austria.
authors.forename: W
authors.initials: W
authors.lastname: Sommergruber
authors.forename: H
authors.initials: H
authors.lastname: Ahorn
authors.forename: A
authors.initials: A
authors.lastname: Zöphel
authors.forename: I
authors.initials: I
authors.lastname: Maurer-Fogy
authors.forename: F
authors.initials: F
authors.lastname: Fessl
authors.forename: G
authors.initials: G
authors.lastname: Schnorrenberg
authors.forename: H D
authors.initials: HD
authors.lastname: Liebig
authors.forename: D
authors.initials: D
authors.lastname: Blaas
authors.forename: E
authors.initials: E
authors.lastname: Kuechler
authors.forename: T
authors.initials: T
authors.lastname: Skern
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism; D012229:Rhinovirus / Q000201:enzymology*; D012965:Sodium Chloride / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D014764:Viral Proteins
chemical_list: D009838:Oligodeoxyribonucleotides; D010455:Peptides; D011480:Protease Inhibitors; D011994:Recombinant Proteins; D014764:Viral Proteins; D012965:Sodium Chloride; D003546:Cysteine Endopeptidases; C057400:picornain 2A, Picornavirus