Studies On The Structure And Function Of Recombinent Cytokine

[Background] Hemangiopoietin (HAPO) is a novel growth factor first purified by our lab. HAPO supports adhesion, proliferation, chemotaxis of both primitive hematopoietic and endothelial cell lineages. The native protein was purified from the urine of patients with alastic anemia. After studying its biological function, our lab recombined a prokaryotic expression system and determined the cytokine function of this recombinant protein.N-terminal sequencing shows that the native protein is one of the alternative splicing products of proteoglycan 4 (PRG4). The N-terminal constitutes of two Somatomedin B homology domains (SMB) encoded by PRG4 exon 2 and 3. The central region is a putative heparin binding domain (pHBD) encoded by exon 4. C-terminal is mucin-like repeats encoded by exon 6 of PRG4. The other two splicing products is absent of exon 4, 5 and of 3, 4, 5, suggesting a foundation to study each domain's function based on the deletion mutation of the protein.At present, research on HAPO is mainly about the pertinence of HAPO and diseases, the physiological function in vivo and in vitro etc. by our lab and the cooperation units. Its monocloned antibody and membrane receptor had been purified and one of the anti-apoptosis pathway triggered by HAPO was PI3K - Akt pathway. However, we know little about its structure except the information of BLAST. Study of the relationship between structure and function will make us probe into other laboratorial results more clearly.[Viscera] Based on the molecular clone and expression system and combined with HPLC, MALDI-TOF-MS, CD, DLS etc., we studied the four aspects about the human recombinant HAPO (rhHAPO) : 1.the prediction structure knowledge of the four domains. 2. the function comparetion between the two oligomeric forms. 3. the association forms comparetion among the different alternative splicing products. 4. whether the putative heparin binding domain binds heparin.[Objective] The satble formation and the oligomrization region of rhHAPO should be identified to illustrate the molecular mechanism of heparin binding and promoting cell adhesion. We want to get the basic chemic and physical characteristics to provide data for the research and exploitation...