Binding determinants of the sialic acid-specific lectin from the slug Limax flavus.

摘要: The specific structural features of 24 N-acetylneuraminic acid derivatives required for the high affinity interaction sialoglycoconjugates with sialic acid-specific lectin from slug Limax flavus were studied by hapten inhibition precipitation. These results provide insight regarding structure binding pocket that exists in L. agglutinin (LFA). alpha-anomer is a very important factor to lectin. carboxylic group makes only moderate contribution binding, since modifications decrease approximately 5-fold. Modification or removal hydroxyl on carbon 4 does not affect binding. However, when C4 epimer was tested, there dramatic suggesting whereas equatorial at contribute introduction an axial sterically hinders interaction. substituent 5-amino occupies role Neu5Ac LFA as well. When acetyl modified addition yield N-glycolyl derivative, we observed 20-fold decrease, while methyl form N-formyl derivative resulted 50-fold decrease. poorest inhibitor all compounds examined, indicating critical N-acetyl LFA. glyceryl tail also appears be inasmuch acetylation C9 periodate cleavage carbons 8 and 9 20- equilibrium constant (K(a)) 3.8 x 10(4) M-1, single site (n = 0.85) per monomer.