NI-MELANIN / ALGINAT BIOMATERIAL COMPLEX AND PROCESS FOR PURIFYING POLYHISTIDIN-LAGGED PROTEINS (HIS-TAG PROTEINS) USING THIS COMPLEX

Abstract

The invention describes a complex biomaterial NA-mdanin / algianate (N-M / A) in the form of spheres with a smooth surface, created by dropping a solution of melanin / algianate (M-A), at a ratio of 2 / 1 (by weight), into a 5% NiCb solution: the particles have a diameter of approximately 0.45 - 0.50 mm in the colloidal state and a size of 0.20 - 0.25 mm in the dry state; the main elements O, C, and Ni are present in the ratios of 40.64%, 31.97%, and 15.91%, respectively, on the surface of the material particles; and the chemical functional groups hydroxyl (-OH), carhonyl (-C-O), amine (-NH2), and imine (-NH-) are present.The -CO-NH- amide on the surface of the material particles has the ability to specifically capture His-tag labeled proteins by forming coordination bonds between the -NH2 and OI groups (of M and His-tag proteins) with Ni2 ions; it can act as an affinity chromatographic substrate to selectively capture His-tag labeled proteins, separating these proteins from protein mixtures with a purity of over 85% or over 95% depending on the desorption conditions. The invention also describes a purification process for His-tag proteins using this biological material complex.