Immunoglobulins interactions with other

As well as their function in binding to antigen, immunoglobulins have other roles within the immune system that necessitate interactions with other proteins such as those of the complement and phagocytic systems. In techniques such as immunofluorescence or in in vivo applications, these interactions can be problematic but can be solved by the use of selective proteolysis to remove parts of the molecule. The polypeptide chains making up the IgG molecule... 

Cell adhesion molecules (CAMs) are transmembrane glycoproteins that act at the cell surface to mediate specific binding interactions with other cell adhesion molecules on adjacent cells or with proteins in the extracellular matrix. They are responsible for the adhesion of various leukocytes with each other, with extracellular matrix and with other cell types. Several classes of molecules capable of mediating adhesion include selectins, integrins, cadherins, and immunoglobulin superfamily members [263-265]. Multiple members from every major family of cell adhesion molecules have been implicated in the development, maintenance, or repair of renal tissues... 

Cassia alata seeds. Several murine antigalactan immunoglobulins have been found to precipitate with willow-bark galactan, presumably by interaction with the (1 -> 6)-linked, non-reducing, D-galactopyranosyl end-groups of the polysaccharide. The chemistry of seed galactomannans has been reviewed, with sections devoted to their occurrence and function, structural aspects, the interactions with other polysaccharides, and commercial uses. ... 

X-Linked hyper-IgM syndrome Defect in gene coding for CD 154 on activated T cell which interacts with receptor on B cells (CD40). B cells make only IgM. Defect also due to mutation affecting switching of IgM to other immunoglobulins. 

At least three other families of plasma membrane proteins are also involved in surface adhesion (Fig. 11-22). Cadherins undergo homophilic ( with same kind ) interactions with identical cadherins in an adjacent cell. Immunoglobulin-like proteins can undergo either homophilic interactions with their identical counterparts on another cell or heterophilic interactions with an integrin on a neighboring cell. Selectins have extracellular domains that, in the presence of Ca2+, bind specific polysaccharides on the surface of an adjacent cell. Selectins are present primarily in the various types of blood cells and in the endothelial cells that line blood vessels (see Fig. 7-33). They are an essential part of the blood-clotting process. 

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