caa a22 4500 397558503 CHVBK 20180308164810.0 cr unu---uuuuu 161202e199611 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021493 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021493 Galectin-1 from Bovine Spleen: Biochemical Characterization, Carbohydrate Specificity and Tissue-Specific Isoform Profiles [Elektronische Daten] [Hafiz Ahmed, Nilda E. Fink, Jan Pohl, Gerardo R. Vasta] Selected biochemical properties, including the charge heterodispersity profile and carbohydrate specificity, of bovine galectin-1 were determined in detail. The lectin was purified through an improved purification protocol that yielded 35-40 mg/kg of wet tissue with a specific activity of 1.7−2× 104 mg−1·ml. The galectin is a homodimer of approximately 14.5 kDa subunits with Emg/ml280 of 0.65 ml·mg−1·cm−1. When stored in the presence of its carbohydrate ligand, the lectin's binding activity remained stable in a non-reducing environment even at room temperature. The optimal pH for binding to the ligand was 6.5·8.0. The overall carbohydrate specificity of the bovine galectin-1 isolated from spleen is similar to that of the galectin isolated from heart and to other mammalian galectins that exhibit "conserved” (Type I) carbohydrate recognition domains (CRDs) [Ahmed, H. and Vasta, G.R. (1994) Glycobiology 4, 545-549], but differs from those from Xenopus laevis and rat intestine domain I. The fluorescence of 4-methylumbelliferyl α-D-galactopyranoside was quenched on binding to bovine spleen galectin-1. Scatchard plots of data obtained at 5, 15, and 30°C showed that the galectin has two sugar exothermic binding sites with association constants of 3.4×105, 1.0×106, and 0.3×105, respectively. Chemical modification studies indicated that histidine, tryptophan, carboxylic acid, and arginine, but not lysine or tyrosine, are involved in the binding to the carbohydrate ligand. On isoelectric focusing, the spleen galectin-1 appeared as six isoforms ranging from pI 4.56-4.88 with main components at pI 4.63 (34.0%), 4.73 (42.6%), and 4.88 (16.6%). The galectin-1 isolated from heart yielded a quali- and quantitatively different profile with four isoforms ranging from pi 4.53-4.73, those with pis of 4.56, 4.63, and 4.73 being common to the spleen homolog. Edman degradation of selected peptides purified from the spleen galectin-1 digest revealed ami no acid sequences identical to those obtained for the heart galectin-1. This suggests that although point mutations in the subunit primary structure may not be the likely source of isolectins, as observed for X. laevis, tissue-specific co- or post-translational modifications may be the possible cause of the differences in the galectin isoform profile between bovine spleen and heart. © 1996 BY THE JOURNAL OF BIOCHEMISTRY Regular Papers nationallicence bovine spleen nationallicence carbohydrate specificity nationallicence conserved CRD nationallicence galectin-1 nationallicence isoform nationallicence Ahmed Hafiz Center of Marine Biotechnology, University of Maryland Biotechnology Institute 701 East Pratt Street, Baltimore, MD 21202 aut Fink Nilda E. Center of Marine Biotechnology, University of Maryland Biotechnology Institute 701 East Pratt Street, Baltimore, MD 21202 aut Pohl Jan Microchemical Facility, Winship Cancer Center, Emory University Atlanta, GA 30322, USA aut Vasta Gerardo R. Center of Marine Biotechnology, University of Maryland Biotechnology Institute 701 East Pratt Street, Baltimore, MD 21202 aut The Journal of Biochemistry Oxford University Press 120/5(1996-11), 1007-1019 0021-924X 120:5<1007 1996 120 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021493 text/html Onlinezugriff via DOI 1 other jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021493 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ahmed Hafiz Center of Marine Biotechnology, University of Maryland Biotechnology Institute 701 East Pratt Street, Baltimore, MD 21202 aut NATIONALLICENCE 700 1- Fink Nilda E. Center of Marine Biotechnology, University of Maryland Biotechnology Institute 701 East Pratt Street, Baltimore, MD 21202 aut NATIONALLICENCE 700 1- Pohl Jan Microchemical Facility, Winship Cancer Center, Emory University Atlanta, GA 30322, USA aut NATIONALLICENCE 700 1- Vasta Gerardo R. Center of Marine Biotechnology, University of Maryland Biotechnology Institute 701 East Pratt Street, Baltimore, MD 21202 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 120/5(1996-11), 1007-1019 0021-924X 120:5<1007 1996 120 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford