title: Hexosaminidase in Trichinella spiralis is a single protein with alpha- and beta-subunits catalytic activities.
abstract: Beta-N-acetylhexosaminidase is expressed as a single protein in Trichinella spiralis and has catalytic properties similar to the alpha- and beta-subunits of human and mouse isoenzymes A and B. It can hydrolyze the artificial substrates, 4-methylumbelliferyl-beta-D-glucosamine and 4-methylumbelliferyl-beta-D-glucosamine-6-sulphate which are respectively hydrolyzed by the beta- and alpha-subunits. The enzyme is thermostable, has a basic isoelectric point, and thus is similar to the B isoenzyme. Northern blotting experiments indicate that the enzyme is encoded by a single gene. Hexosaminidase from Trichinella spiralis shows that the substrate specificities of alpha- and beta-subunits precede the duplication of their genes.
authors.affiliation: Dipartimento di Biologia Cellulare e Molecolare, Sezione di Biochimica e Biologia Molecolare, Università degli Studi di Perugia, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Costanzi
authors.forename: T
authors.initials: T
authors.lastname: Beccari
authors.forename: M A
authors.initials: MA
authors.lastname: Della Fazia
authors.forename: G
authors.initials: G
authors.lastname: Servillo
authors.forename: A
authors.initials: A
authors.lastname: Orlacchio
authors.forename: C
authors.initials: C
authors.lastname: Tassi
authors.forename: F
authors.initials: F
authors.lastname: Bruschi
mesh_terms: D000818:Animals; D002384:Catalysis; D004789:Enzyme Activation; D005456:Fluorescent Dyes; D017238:Genes, Helminth; D008970:Molecular Weight; D018510:RNA, Helminth / Q000302:isolation & purification; D013379:Substrate Specificity; D017160:Trichinella spiralis / Q000201:enzymology*; D001619:beta-N-Acetylhexosaminidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D005456:Fluorescent Dyes; D018510:RNA, Helminth; D001619:beta-N-Acetylhexosaminidases