Objective       To determine the effect of an amphotropic recombinant protein of fibronectin module Ⅲ7-10/cadherin 11 EC1-2 (rFN/CDH) on cell adhesion and differentiation in human mesenchymal stem cells (hMSCs).       Methods       FN and CDH11

as two pre-molecules of our objective recombinant protein

were analyzed bioinformatically to acquire the structural sequences and functional groups. The functional fragments of FN and CDH11 were integrated using a homology modeling strategy. The fragments of FNⅢ7-10 and CDH11 EC1-2 were spliced by SOE-PCR and then inserted into the expression plasmid of pET-22b to construct a reconstructed vector. After transforming the vector into Rsoetta-gami (DE3) strain and optimizing the experimental parameters

rFN/CDH was induced to express using IPTG and then purified. Further

Western blotting was employed to verify the protein. While

centrifugal cell adhesive assay and osteoblastic induction were used to determine the bioactivity of the protein in vitro.       Results       The prokaryotic expression vector pET22b-FNⅢ 7-10/CDH11 EC1-2 encoding the objective fusion gene was successful constructed. The rFN/CDH protein was in soluble expression

with the purity reaching 96%

and identified to have the accuracy of the individual expression of fusion protein properties. Additionally

cell centrifugal adhesive assay demonstrated that the tissue-culture treated polystyrene (TCPS) coated with rFN/CDH adhered more hMSCs with differentiation potential of osteoblasts

as compared to single FN and CDH. Alkaline phosphatase (ALP) activity and osteocalcin (OCN) gene/protein expression

as the early and late markers for osteoblastic differentiation

indicated that rFN/CDH further promoted ALP activity and OCN gene expression.       Conclusion       A prokaryotic expression vector encoding rFN/CDH fusion gene is successfully constructed

and the fusion protein is purified and identified. The obtained rFN/CDH possesses excellent capacity in promoting osteoblastic adhesion and ossification

which achieves the functional integration of FN and CDH11. It can be used as an ideal construction of biomimetic modification of molecular for biological interface.