Studies of the carbohydrate-carbohydrate interaction between lactose and GM3 using Langmuir monolayers and glycolipid micelles

This paper describes studies of the carbohydrate-carbohydrate interaction (CCI) between micelles of a lactosyl lipid and monolayers of the glycosphingolipid GM(3). The lactose Lac.GM(3) interaction is involved in B16 melanoma cell adhesion and signaling processes, and a thorough understanding of the molecular details of this CCI is important for the design of new anti-adhesive and anti-metastatic agents. In this paper, we examine the influence of variations in divalent cations and subphase ionic strength on the Lac.GM(3) interaction. Our results indicate that, in the absence of divalent cations, the Lac.GM(3) CCI is strengthened at higher sodium chloride concentrations in the subphase. In contrast, when divalent cations are present in solution, the CCI is not as sensitive to ionic strength. These results suggest a role for both cation dependent as well as independent interactions in the Lac.GM(3) CCI.