title: Amino acid sequence of Egyptian goose egg-white lysozyme and effects of amino acid substitution on the enzymatic activity.
abstract: The amino acid sequence of Egyptian goose lysozyme (EGL) from egg-white and its enzymatic properties were analyzed. The established sequence had the highest similarity to wood duck lysozyme (WDL) with five amino acid substitutions, and had eighteen substitutions difference from hen egg-white lysozyme (HEL). Tyr34 and Gly37 were found at subsites E and F of the active site when compared with HEL. The experimental time-course characteristics of EGL against the N-acetylglucosamine pentamer substrate, (GlcNAc)(5), revealed higher production of (GlcNAc)(4) and lower production of (GlcNAc)(2) when compared with HEL. The saccharide-binding ability of subsites A-C in EGL was also found to be weaker than in HEL. An analysis of the enzymatic reactions of five mutants in respect of positions 34, 37 and 71 in HEL indicated the time-course characteristics of EGL to be caused by the combination of three substitutions (F34Y, N37G and G71R) between HEL and EGL. A computer simulation of the EGL-catalyzed reaction suggested that the time-course characteristics of EGL resulted from the difference in the binding free energy for subsites A, B, E and F and the rate constant of transglycosylation between EGL and HEL.
authors.affiliation: Department of Bioscience, School of Agriculture, Tokai University, Aso, Kumamoto, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kawamura
authors.forename: Gen
authors.initials: G
authors.lastname: Toshima
authors.forename: Yuki
authors.initials: Y
authors.lastname: Chijiiwa
authors.forename: Takao
authors.initials: T
authors.lastname: Torikata
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Araki
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D055162:Biocatalysis; D020134:Catalytic Domain; D002645:Chickens; D003198:Computer Simulation; D004372:Ducks; D004529:Egg White / Q000737:chemistry; D005260:Female; D005777:Geese; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009113:Muramidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D011994:Recombinant Proteins; C421864:hen egg lysozyme; D009113:Muramidase; D000117:Acetylglucosamine