Study On Adhesion Behavior Of Proteins To Material Suifaces Under Micro-conditions And Macro-conditions

The adhesion behavior of proteins frequently occurs in a variety of biological activities.It is known that the adhesion behavior of proteins plays an important role in many biological reactions such as cell proliferation and growth,microbial colonization,platelet adhesion and thrombosis.From the perspective of tissue engineering,the good adhesion of certain proteins to the surface of biomaterials helps cell adhesion and proliferation and promotes regeneration and healing of damaged tissues.Therefore,it is of great significance to study the adhesion behavior of proteins and material surfaces.In this paper,the adhesion behavior of Si-Tag and LCIM1 with adhesion to silica and polypropylene were studied respectively.Since Si-Tag protein contains a large number of positive charges,there will be electrostatic interaction between Si-Tag protein and silanol（-Si OH）.In addition,Si-Tag protein doesn’t have identified three-dimensional structure,and its own structure will produce adaptive deformation when adhesion behavior occurs.These reasons lead to the strong adhesion of Si-Tag protein and Si O₂.However,it is not clear how strong the adhesion of a single Si-Tag protein to Si O₂ is,and whether the strong adhesion under the microscopic conditions still exists under the macroscopic conditions.The purpose of this topic is to investigate the adhesion of Si-Tag protein to Si O₂surface and whether this strong adhesion behavior still exists under macroscopic conditions.The adhesion behavior of recombinant Si-Tag to Si O₂ glass slides under microscopic conditions was studied by single-molecule force spectroscopy technique of atomic force microscope.At the same time,a hydrogel prepared from sulfhydryl-functionalized and maleimide-functionalized polyethylene glycol polymers was used as a carrier,and the recombinant Si-Tag protein was modified on the hydrogel.The adhesion behavior of hydrogels to Si O₂ substrates under macroscopic conditions was investigated by micro-force measuring balance.The experimental results show that the adhesion of Si-Tag to Si O₂ glass slides under microscopic conditions is 597 p N,and the adhesion of Si-Tag-modified hydrogels to Si O₂glass slides under macroscopic conditions is118.68 N/m².The adhesion force of the protein-modified hydrogel without Si-Tag was only 3.16 N/m².The results show that the strong adhesion of Si-Tag to silica glass slides still exists under macroscopic conditions.In addition,the adhesion behavior of the recombinant protein of LCI-modified protein LCIM1 to polypropylene was studied by the same experimental method.LCI is an antibacterial peptide and a surface polymer-binding peptide with obvious adhesion behavior to PP.Modification of LCI can increase the adhesion to PP to achieve the purpose of functionalizing PP.The experimental results of single-molecule force spectroscopy show that the adhesion force of LCIM1 to PP under microscopic conditions is 60 p N.The results of the micro force measurement balance showed that the average adhesion force of LCIM1 to PP under macroscopic conditions was 345.66N/m².This indicates that LCIM1 has strong adhesion to PP under macroscopic conditions.The research results of this subject quantified the adhesion between Si-Tag protein and Si O₂ glass slides under micro and macro conditions,and quantified the adhesion between LCIM1 and PP under micro and macro conditions.It provides an important basis for other biological functions,and has the potential to be used as a fingerprint in single-molecule force spectroscopy in atomic force microscopy or as a binding tag for materials such as functionalized Si O₂ or PP.It also provides important ideas for the study of adhesion behavior of other proteins.