title: Differences in the betaC-S lyase activities of viridans group streptococci.
abstract: betaC-S Lyase catalyzes the alpha,beta-elimination of L-cysteine to hydrogen sulfide, which is one of the main causes of oral malodor and is highly toxic to mammalian cells. We evaluated the capacity of six species of oral streptococci to produce hydrogen sulfide. The crude enzyme extract from Streptococcus anginosus had the greatest capacity. However, comparative analysis of amino acid sequences did not detect any meaningful differences in the S. anginosus betaC-S lyase. The capacity of S. anginosus purified betaC-S lyase to degrade L-cysteine was also extremely high, while its capacity to degrade L-cystathionine was unremarkable. These findings suggest that the extremely high capacity of S. anginosus to produce hydrogen sulfide is due to the unique characteristic of betaC-S lyase from that organism.
authors.affiliation: Department of Preventive Dentistry, Kyushu University, Faculty of Dental Science, Fukuoka 812-8582, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Masahiro
authors.initials: M
authors.lastname: Negishi
authors.forename: Akiko
authors.initials: A
authors.lastname: Amano
authors.forename: Takahiko
authors.initials: T
authors.lastname: Oho
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nakano
mesh_terms: D001483:Base Sequence; D013437:Carbon-Sulfur Lyases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003540:Cystathionine / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism; D015394:Molecular Structure; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D034366:Streptococcus anginosus / Q000201:enzymology / Q000235:genetics; D034363:Viridans Streptococci / Q000201:enzymology* / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D011994:Recombinant Proteins; D003540:Cystathionine; D013437:Carbon-Sulfur Lyases; D003545:Cysteine; D006862:Hydrogen Sulfide