A study on the interaction between concanavalin A and glycogen by light scattering technique and its analytical application

The mixture of concanavalin A (Con A) and glycogen shows strong light scatt ering character. Based on it, the interaction between Con A and glycogen wa s studied on a common spectrofluorimeter by light scattering technique. Man y factors affecting the light scattering intensity (LSI), such as pH, tempe rature, reaction time, ion strength and the denaturing agent of protein wer e studied in detail. Experimental results showed that the LSI reached its m aximum after mixing Con A with glycogen for about 20 min in pH 7.4 Tris-HCl buffer at 37 degreesC. The results also suggested that the conformation of Con A was critical for its unique binding affinity to glycogen. Electrosta tic forces should not be the primary interaction between glycogen and Con A . Under proper experimental conditions, the determination method for glycog en by light scattering technique was developed. The glycogen determination can be performed in the range of 0.45-32.0, 0.50-32.0 and 0.32-24.0 mug/ml for Rabbit liver glycogen (Rb. Gly), Oyster glycogen (O Gly) and Clam Glyco gen (C Gly), respectively. The influence of co-existing substances such as proteins, mono- and di-saccharides and metal ions was evaluated, and little interference came from the foreign substances. The determinations of glyco gen in synthetic samples demonstrated that the recovery rate was in the ran ge of 98.1-103% and the relative standard deviations (RSD) were lower than 5.0%. (C) 2001 Elsevier Science B.V. All rights reserved.