Preliminary Study On A New Mussel Foot Protein Biological Adhesive

The marine mussel foot proteins(Mfp3)has high strength,high toughness,high water resistance and very strong matrix adhesion function.It also has good biocompatibility and biodegradability.It is a kind of biological adhesive with great advantages and potential.Studies have shown that the stickiness of Mfp3 is related to the tyrosine of post-translational modification,which named DOPA.In vitro,due to poor water solubility of Mfp3,low enzyme selectivity and low catalytic efficiency and no selectivity of modification site,the product of enzyme catalyzed recombinant expression of Mfp3 can not be equivalent to natural extract.The genetic encoding unnatural amino acid(GEUAA)technology can introduce the modified amino acid to the specific site of the protein in the body,and can achieve the high efficiency and localization of the DOPA modification of Mfp3.Based on GEUAA technology,we constructed a library containing Escherichia coli Pyrrole tyrosine aminoacyl tRNA synthetase mutation library-HJ1,it's capacity as high as 10~6.An orthogonal aminoacyl tRNA synthetase for HepoK was obtained,which verified the validity of the library.SUMO tag was added to the N terminal of Mfp3 protein to increase the water solubility.The SUMO-Mfp3 fusion protein could produce the adhesion force of>0.037 MPa by enzymatic catalysis.Meanwhile,HJ1 library is being used to screen DOPA analogues L-minosine.The above results provide a solid foundation for the development of new biological adhesive of Mfp3.