A protein, immunologically similar to Tamm-Horsfall glycoprotein, produced by cultured baby hamster kidney cells

Abstract

Tamm-Horsfall glycoprotein was isolated from the urine of Syrian hamsters. It is similar in many of its chemical and physical properties to the related proteins from man and from rabbit except that it appears to be devoid of sialic acid. There was a complete cross-reactivity between the Tamm-Horsfall glycoproteins from the three species mentioned and the respective antiserum produced against each of them. A line of cultured baby hamster kidney cells, adapted to grow in suspension, was shown to produce a glycoprotein, or family of glycoproteins, which was immunologically closely similar to the urinary Tamm-Horsfall glycoprotein. Cells were grown in presence of $^{14}$C-glucosamine and labelled antigenic material was isolated by affinity chromatography, both from sonicates of the cells and from the medium in which they had been grown. Columns made by coupling rabbit antiserum (raised against hamster Tamm-Horsfall glycoprotein) to Sepharose 2B were prepared for the purpose of affinity chromatography, and the technique was demonstrated to be specific. The group of antigenic glycoproteins isolated from the medium in which the kidney cells had been cultured is similar to, but not identical with, hamster urinary Tamm-Horsfall glycoprotein with regard to its composition and probable molecular size. The relations between these glycoproteins require further study.