title: Structure of the buffalo secretory signalling glycoprotein at 2.8 A resolution.
abstract: The crystal structure of a 40 kDa signalling glycoprotein from buffalo (SPB-40) has been determined at 2.8 A resolution. SPB-40 acts as a protective signalling factor by binding to viable cells during the early phase of involution, during which extensive tissue remodelling occurs. It was isolated from the dry secretions of Murrah buffalo. It was purified and crystallized using the hanging-drop vapour-diffusion method with 19% ethanol as the precipitant. The protein was also cloned and its complete nucleotide and amino-acid sequences were determined. When compared with the sequences of other members of the family, the sequence of SPB-40 revealed two very important mutations in the sugar-binding region, in which Tyr120 changed to Trp120 and Glu269 changed to Trp269. The structure showed a significant distortion in the shape of the sugar-binding groove. The water structure in the groove is also drastically altered. The folding of the protein chain in the flexible region comprising segments His188-His197, Phe202-Arg212 and Tyr244-Pro260 shows large variations when compared with other proteins of the family.
authors.affiliation: Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Abdul S
authors.initials: AS
authors.lastname: Ethayathulla
authors.forename: Devendra B
authors.initials: DB
authors.lastname: Srivastava
authors.forename: Janesh
authors.initials: J
authors.lastname: Kumar
authors.forename: Kolandaivelu
authors.initials: K
authors.lastname: Saravanan
authors.forename: Sameeta
authors.initials: S
authors.lastname: Bilgrami
authors.forename: Sujata
authors.initials: S
authors.lastname: Sharma
authors.forename: Punit
authors.initials: P
authors.lastname: Kaur
authors.forename: Alagiri
authors.initials: A
authors.lastname: Srinivasan
authors.forename: Tej P
authors.initials: TP
authors.lastname: Singh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002020:Buffaloes; D018360:Crystallography, X-Ray; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000737:chemistry* / Q000235:genetics; D006031:Glycosylation; D008969:Molecular Sequence Data; D009154:Mutation; D011487:Protein Conformation; D017510:Protein Folding; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D017931:DNA Primers; D006023:Glycoproteins