Abstract: Purified C-terminally truncated insulin-like growth factor binding protein-5 (IGFBP-5) compounds are described. The compounds are mitogenic and bind to insulin-like growth factors (IGFs) with decreased affinity. The C-terminally truncated IGFBPs can be produced recombinantly.

Abstract: Methods of enhancing bone formation and/or bone accretion in vivo are disclosed. The methods utilize IGFBP-5 polypeptides, including full-length IGFBP-5, analogs or fragments thereof. These molecules can be delivered alone or in combination with agents which inhibit bone resorption or additional agents that enhance bone accumulation.

Abstract: Purified compounds comprising truncated insulin-like growth factor binding protein (IGFBP) capable of binding to an antibody specific for the compound or to an insulin-like growth factor wherein the truncated IGFBP has a decreased affinity for insulin-like growth factors (IGFs) are described. Recombinant DNA molecules encoding the truncated IGFBPs are also described along with recombinant microorganisms and cell lines containing the DNA molecules and methods for producing the truncated IGFBPs using recombinant hosts containing the relevant DNA molecules. Methods for stimulating mitogenic activity and also for treating a bone disorder in mammals are also described.

Abstract: Methods for stimulating osteogenesis using C-terminally truncated insulin-like growth factor binding protein-5 (IGFBP-5) compounds and derivatives thereof are described. The IGFBP-5 polypeptides used in the methods are mitogenic and can be combined in compositions with insulin-like growth factor (IGF).