Interaction Of Light Chain And Heavy Chain Of Kinesin-1 Protein And The Crystal Research Of The Complex

Molecular motors are the general terms for a class of macromolecular that convert the chemical energy of adenosine triphosphate into kinetic energy in living creature.In the eukaryotic cells,there are three main types of molecular motors for the cargo transportation:myosin,dynein and kinesin.The myosin is used to transport the cargos along the microfilament,while the dynein and the kinesin walks along the microtubule.There are various kinds of transported goods,including membrane structural vesicles,protein complexes,messenger RNA and organelles,and so on.In polarized cells,such as neurons,the subcellular location of various goods is particularly important.In some neurodegenerative diseases,such as Alzheimer's disease and Huntington's disease,the pathogenesis is closely related to the absence of molecular motor function.When the function of the molecular motor is limited,it causes the disorder of material transportation in the cell,thus affecting the normal operation of life activities.In this thesis,we focus on the Kinesin super family member,Kinesin-1.And we explore the interaction between the kinesin-1 heavy chain and light chain.Because the light chain is between the cargo and the heavy chain,it is very important in material transportation.We used the prokaryotic expression system to express the kinesin-1 family member,KIF5B,and the light chain of KIF5B protein,KLC2,KLC3 and KLC4.In vitro,we found the core binding area of the two protein,which is the 40 amino acid residues in the 781 to 821 range of mKIF5B protein.At the same time,we obtained the complex crystal of the kinesin light chain mKLC2 and heavy chain mKIF5B.By means of X-ray crystallography,the resolution of the diffraction patterns is 8 emm.We need to do further crystal screening and optimization.Through the multi-angle static light scattering experiment,the ratio of the kinesin light chain mKLC2 and heavy chain mKlIF5B in the complex is 2:2.It is concluded that the model of the complex is two heavy chains form dimer structure,and each heavy chain is combined with a light chain.