The investigation of the KLF4 conformational changes at different conditions by Multi-spestroscopic and Zetapotential : A novel view of the cancer therapy

index in stem cells and tumors with bi-functional role as an oncogenic and tumor suppressorfactor, the study of stability and instability of this protein has an important role in treatment ofcancers related to KLF4. Tumor suppressor function of KLF4 has been reported in severalhuman cancers including colon, lung, esophageal, gastric, and bladder cancers due to itsloss of expression. Ectopic overexpression of KLF4 has been shown to be associated withinhibition of cell proliferation, apoptosis induction, cell cycle arrest; whereas the inactivationo f KLF4 expression has been shown to promote tumor progression.The technices such asFluorescence spectroscopy, UV-visible spectroscopic, Circular dichroism, Zeta potentialmeasurement and Stoke radius measurement were used. Therefore, 2ml of %0.01 KLF4 inKH2PO4 buffer in various amounts of pH and ionic strengths was added and the ranges weremeasured,by mentioned assays.:Secondary structural changes of protein at differentconditions had been studied by circular dichroism, which shows the dependence of protein topH, which at pH=7.4 protein maintains it’s secondary structure better and from pH=7.4 tothe higher and lower pH, secondary structure will experience many changes.In themeasurement of KLF4 protein’s zeta potential, hydrophobic and electrostatic forces playa major role in stability and instability of proteins structure. With increasing ionic strength ateach pH, the zeta potential will decrease, so that the amount of protein’s charge andprotein electrostatic interactions will reduce and result in increasing of hydrophobicity whichshows the structural instability of KLF4 protein caused by hydrophobicity of the interaction. Inother hand electrostatic interactions is an important factor in inceasing of zeta potential inpH=7.4.According tothe results obtained from the Stokes radiuse and intrinsic viscosity,inresponse to the presence of KLF4 protein in different environmental conditions and ionicstrengths, proves the structural stability of KLF4 in pH=7.4 and abnormality and instability ofthat in pH=5. These findings show that the protein stability is pH dependant and differentenvironmental conditions (such as solvent, ionic strength) could provide circumstances forstability or instability of this protein wich can help us to find the therapeutic strategies forcancers such as colorectal, breast, stomach cancers and etc.

کلیدواژه ها:

KLF4 ، Cancer therapy ، Spectroscopy ، Oncogene factor ، Tumor suppressor factor