Department of Biochemistry and Molecular Biology
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Browsing Department of Biochemistry and Molecular Biology by Author "Animashaun, T."
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- ItemOpen AccessPurification and Characterisation of Lectin from Bowringia Miladbraedii Harms Seeds(Obafemi Awolowo University, 1985) Alakija, Augusus Adegbolamiyo Olufemi; Animashaun, T.; Aboderin, A.A.Lectin was extracted from Bowringia mildbraedii Harms seeds and shown to agglutinate red blood cells nonspecifically. The chromatography using different grades of Sephadex did not give a very good separation of the lectin. Purification of the lectin by Sepharose 68 chromatography followed by metal chelate affinity chromatography was compared with purification by Sepharose 6B followed by ion-exchange chromatography using DEAE cellulose. The latter method was preferred and yielded a protein which behaved as a single protein on polyacrylamide gel electrophoresis. It was deduced that the lectin occured as a tetrameric protein with two subunits A and B having approximate molecular weight of 14,000 and 16,000 respectively from experiments with SOS-PAGE in the presence of 2, β-mercaptoethanol. The molecular weight of the lectin is approximately 60,000. The B. mildbraedii lectin precipitated Afzelia africana polysaccharide with remarkable specificity and failed completely to form precipitin bands in agargel double diffusion plates with other polysaccharides tested even at varying concentrations. The haemagglutinating and polysaccharide precipitating activity of the lectin is appreciably inhibited by µ-methylD-mannoside, D-mannose and D-glucose.
- ItemOpen AccessPurification and Characterization of Lectins from Abrus Species.(Obafemi Awolowo University, 1985) Caiquo, Aspect Wallace Kyemenu; Animashaun, T.Saline extracts prepared from Abrus precatorius and Abrus fructiculosus seeds agglutinated red blood cells. The agglutination was inhibited by D-galactose and lactose. The lectins bound to Sepharose 6B and were eluted with D-galactose. These lectins were separated into an agglutinin and a toxin by chromatography on Diethyl amino ethyl (DEAE) cellulose. The toxin from Abrus fructiculosus seed was named fructin' to distinguish it from Abrus precatorius seed toxin, abrin. In sodium dodecyl - polyacrylamide gel electrophoresis, (SDS-PAGE) fructin and abrin gave single bands with molecular weights (proposed) 60,320 and 62,500 respectively. After treatment with mercaptoethanol, fructin and abrin were split into 2 bands each with molecular weights 32,360 and 30,200 (fructin), 36,520 and 28,800 (abrin). The agglutinins gave 2 bands each in SDS-PAGE with corresponding molecular weights of 57,480 and 55,650 (A. fructiculosus agglutinin) and 59,600 and 56,380 (A. precatorius agglutinin). The proposed native molecular weights are 113,130 (. fructiculosus agglutinin) and 115,980 ( A. precatorius agglutinin), Alen treated with SDS and f - mercaptoethanol, the agglutinins were split into 3 bands each with corresponding agar molecular weights 38,460, 33,500 and 28,180 (,. fructiculosus agglutinin) and 40,790, 35,590 and 31,260 (A.precatorius agglutinin). The saline extracts from the two seeds did not interact with Afzelia africana polysaccharide in agar gel double diffusion studies. The toxicity of fructin and A. fructiculosus agglutinin was established on mice, with fructin being about 150 times more toxic than the agglutinin. Antisera formed against abrin and A. precatorius agglutinin did not interact with saline extracts of A. fructiculosus, fructin and A. fructiculosus agglutinin.