Biochemical study of KB-cell receptor for adenovirus

Abstract

Three different approaches were used in an attempt to characterize the [human oral carcinoma] KB-cell receptor for adenovirus: affinity chromatography, immunoadsorption and cross-linking with a cleavable bifunctional reagent. The 1st system used an affinity gel consisting of adenovirus-fiber projection linked to Sepharose matrix by an intermediate bis(aminopropyl)amine arm, the amino groups of the fiber ligand being preserved by prior citraconylation. The 2nd system consisted of adenovirus complete penton capsomere attached to anti-(penton base) antibody and cross-linked to polyacrylamide particles with glutaraldehyde. In this latter affinity model, the penton-fiber projection was appropriately oriented outwards, as in the virus particle. Both affinity systems permitted isolation from a KB-cell plasma membrane extract of fiber-binding and penton-fiber-binding protein material, which inhibited adenovirus attachment. The penton-immunoadsorbent appeared more efficient and more specific than the affinity column of fiber-bis(aminopropyl)amino-Sepharose gel in specific activity of inhibition of adenovirus attachment. The 3rd method consisted of reversibly cross-linking KB-cell receptor proteins with adenovirus particles by a cleavable di-imidoester and isolation of the complexes by sucrose-density-gradient centrifugation. Polypeptide analysis on sodium dodecyl sulfate/polyacrylamide gel of labeled KB-cell surface proteins, selected by the different procedures, showed that 3 major protein subunits of 78,000, 42,000 and 34,000 MW were common to the 3 selection systems. A possible model for the structure and function of the KB-cell receptor for adenovirus is discussed.