Critical concentration of Glucose changes human serum albumin conformation: Circular Dichroism (CD)and UV Spectroscopyapproaches

Abstract

HSA plays an important role in transporting metabolites and drugs throughout the vascular system. In as much as its performance is very vital in the presents of different kinds of ligands at the specific body temperatures, its examination is crucial. This molecule can undergo increased glycation in diabetes. Therefore, glucose as the one of the most fundamental ligands dealing with albumin in human body is examined in this study at 100 mg/dl concentration in correspond to normal condition on human body, 175 mg/dl as a kidney glucose tolerance point and also 400 mg/dl as the critical point at the two most important temperatures in diabetic patients. Thermal conformational changes of (HSA) are important. These conformational alterations are accompanied by a mild alteration of secondary structures. For this reason, possible secondarystructural changes of HSA in presence of glucose has beeninvestigated by circular dichroism (CD) using Hepes bufferat the normal temperature 37˚C and 42˚C as a high fever condition.UV spectroscopystudies confirmed CD findings and indicate that critical concentration of glucoselead to generation of new structural feature of albumin similar to 42 o C. However, as the temperature increases from 37˚C to 42˚C this process is no more capable of responding to glucose concentration changes.These results indicate that the native form of HSA is changed in the severe diabetic condition; likewise, same consequences can be achieved as the temperature arises from 37˚C to 42˚C.