Structural and Functional Changes of Laminin and Type IV Collagen After Nonenzymatic Glycation

Laminin and type IV collagen are two major basement membrane glycoproteins; they are large multidomain macromolecules that are involved in two types of functions. First, they provide the structural framework of all basement membranes, and second, they interact with cell-surface molecules and are key to adhesion, spreading, and proliferation of cells. We summarize experimental evidence that nonenzymatic glucosylation of these two macromolecules in vitro alters their structure, their ability to polymerize, and their ability to promote cell adhesion. Additional studies are needed to document these changes in situ and therefore extend these conclusions to intact basement membranes.