The ultimate goal of this project is to identify natural variants of the insulin-like growth-factor carrier protein (IGF-CP) that exhibit enhanced therapeutic potential. Such IGF-CP's may only be synthesized in specific tissues where they interact with IGF's to carry out particular functions. For example I the IGF-CP found in the wound fluid may have different properties (i.e., stability, affinity for IGF) from that found in the serum. Several tissues and cell lines that have been shown to produce IGF-CP's as well as IGF's will be the sources for the potential IGF-CP variants. To test the feasibility of this approach, CDNA libraries corresponding to several human tissues and cell lines will be obtained or constructed and rapidly screened for the presence of IGF-CP genes via PCR amplification during Phase I. IGF-CP genes will be isolated from these libraries, characterized, and compared at the DNA sequence level. During Phase II, variant genes will be expressed and their products tested for their ability to function as IGF-CP's.
Anticipated Results:Tissue-specific forms of IGF-CP, that is, CP variants, could exhibit enhanced therapeutic potential, particularly in the treatment of osteoporosis or the acceleration of bone and wound healing.National Institute Of General Medical Sciences (NIGMS)
