title: Characterization of a novel oligomeric SGNH-arylesterase from Sinorhizobium meliloti 1021.
abstract: A novel oligomeric SGNH-arylesterase (Sm23) from Sinorhizobium meliloti 1021 was characterized using biochemical and biophysical methods. A sequence comparison of Sm23 with other SGNH members confirmed the presence of catalytic triad (Ser(10), Asp(187), and His(190)) and oxyanion holes (Ser(10)-Gly(50)-Asn(90)). The wild type enzyme was able to hydrolyze p-nitrophenyl acetate, alpha- and beta-naphthyl acetate, while S10A mutant completely lost its activity. Structural properties of Sm23 were investigated using circular dichroism (CD), fluorescence, dynamic light scattering (DLS), chemical cross-linking, electron microscopy (EM), and time of flight (TOF) mass spectrometry. Furthermore, spherical or globular aggregates were observed with 1-butyl-3-methylimidazolium tetrafluoroborate, while amorphous aggregates were formed with 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.
authors.affiliation: Department of Molecular Science and Technology, Graduate School of Interdisciplinary Programs, Ajou University, Suwon 443-749, South Korea.
authors.forename: Heejin
authors.initials: H
authors.lastname: Hwang
authors.forename: Seungbum
authors.initials: S
authors.lastname: Kim
authors.forename: Sangyoung
authors.initials: S
authors.lastname: Yoon
authors.forename: Yeonwoo
authors.initials: Y
authors.lastname: Ryu
authors.forename: Sang Yoon
authors.initials: SY
authors.lastname: Lee
authors.forename: T Doohun
authors.initials: TD
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D057075:Enzyme Assays; D008027:Light; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012542:Scattering, Radiation; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D016962:Sinorhizobium meliloti / Q000201:enzymology*; D012997:Solvents; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D012997:Solvents; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase