Human serum albumin (HSA) is one of the most important blood protein playing various essential roles. It regulates the osmotic pressure and effectively transports a variety of ligands such as drugs, vitamins, fatty acids, ions due to its specific binding properties. It is postulated in the literature that as a result of various pathological states, albumin can be modified and may lose some of its binding properties. For example, a non-enzymatic glycation process occurring in diabetes is one of the most common modifications that contribute to various impairments in the binding affinity. The glycated albumin is considered to be a more efficient marker for glycemic control compared to the usually exploited hemoglobin. Therefore, the goal of this work is a thorough physicochemical characteristics of glycated albumin (glyHSA) in comparison to the normal HSA. Accordingly, the electrophoretic mobility and the hydrodynamic diameter of both albumins were determined as a function of pH and ionic strength using the micro-electrophoresis and DLS methods. The obtained results indicate that these parameters are similar for both forms, which suggests a low impact of glycation on the net charge and the size of the protein. Subsequently, the monolayers of normal and glycated albumins were prepared on negatively charged polystyrene latex particles (800 nm in diameter ). The adsorption process was carried out for the range of ionic strength 10-3 to 0.15 M NaCl at pH 3.5. The maximum coverage for 0.15 M was 1.4 and 1.3 mg m-2 for HSA and glyHSA, respectively. It was confirmed that albumins were irreversibly adsorbed that allows one to perform extensive studies of ligand bindings using the electrokinetic methods.
Acknowledgements: Grant PRELUDIUM 2012/07/N/ST5/02219.
nckujda@cyf-kr.edu.pl
