The Property Of ATPase For HSP70 And HSP110

Heat shock protein(Hsp)is a normal biological proteins existence in all species.Heat shock proteins Hsp70 and Hsp110 are two important types,which play a key role in maintaining the normal life of the organism.First,as a molecular chaperone protein,it can help fold the correct folding of proteins,accelerate the recovery of normal protein synthesis.The main function of Hsp70 as a molecular chaperone is to help other proteins to fold or prevent mistaken folding caused by its hydrophobic bond generated by the phenomenon of protein aggregation phenomenon.As necessary factor for the function of Hsp70(Nucleotide Exchange Factor,NEFs),Hsp110 showed a higher activity than Hsp70 in preventing denaturation protein aggregation.However,Hsp110 did not have protein folding activity similar to that of Hsp70.Hsp70 is known as foldase,and Hsp110 is known as holdase.Whether Hsp70 or Hsp110 want to play its role,they need ATP binding or ATP hydrolysis to understand the function of Hsp,that is very useful to know the relationship with Hsp and ATP.In this study,the heat shock protein in prokaryotic DnaK,heat shock protein in eukaryotic Bip as a typical Hsp70 were studied.The most extensively selected Sse1 in eukaryotic clock is studied as a typical Hsp110.The isotope-labeled P32 ATP was used as the hydrolysis standard.Heat shock protein DnaK,as an important Hsp70 protein in E.coli,is often used as a model for studying Hsp70s.By studying the protein structure of DnaK,it was found that SBD domain existed at the peptide binding site,and the binding of different peptides directly affected the efficiency of hydrolysis of ATP with DnaK.When 2NR was combined at DnaK,the hydrolysis rate of 2NR was 1.8 times as high as that of 2NR at 40 ?M,and 2.4 times as high as that of 2NR at 80 ?M,and 3.8 times of that at 160 ?M.When combined with the linear 2NR,40 ?M rate of 3.65 times normal,80 ?M for the normal 6.4 times,160?M for 9.4 times the normal rate of hydrolysis.Heat shock protein Bip as a DnaK homology,in maintaining the stability of the human body plays an important role.Through the study of the crystal structure,it was first time be found that the ability to hydrolyze ATP into AMP at low pH,especially at pH 4.5.The discovery of human cells will be used for new ATP utilization.Heat shock protein Sse1 as a typical protein in in eukaryotic,has 8 different loop in SBD domain,and after we mutant these loop,we got 7 different proteins,these are Sse1-xun-loopl2,Sse1-xun-loop23,Sse1-xun-loop34,Sse1-xun-loop45,Sse1-xun-loop56,Sse1-xun-loop67,Sse1-xun-loop7.The results showed that the four sites of loop23,loo34,loop56 and loop67 had the greatest influence on the hydrolysis of ATP,and the growth experiments showed the same conclusion for these four binding site.When these sites were mutant,the function of Sse1 was affected.The binding ability of mutant protein to polypeptide substrate was detected by fluorescence polarization technique,and binding to fluorescently labeled TRP2 was also used to obtain the result that the binding sites of loop23,loo34,loop56 and loop67,as well as the ATPase and growth experiments,are different with the normal binding of Sse1.