ABSTRACT
The suggested functions of fibronectm are all related to its binding affinity to vastly different biological substances, especially cell surfaces. How is it possible for a single protein to bind negatively charged compounds, such as heparin and DNA, and positively charged compounds, such as polyamines, and how can it bind to proteins with very different structures, such as collagen and fibrinogen? Within the last years a number of laboratories have obtained fragments from fibronectin containing one or more of the specific binding activities, which suggests that fibronectin is a domain protein with the binding activities located in different domains. To provide a more precise characterization of the binding domains of fibronectin, it is of obvious interest to determine the primary structure of fibronectin preferentially on both the protein 8level and the DNA level. In this chapter the available sequence information of fibronectin is presented, based both on results obtained from human [1-5] and bovine [6-11] plasma fibronectin and on results from recombinant DNA work on chicken genomic DNA [12] and human [13, 14] and rat [14a] cDNA.
