Ingemar Berggård

Gel filtration of the low molecular weight carbohydrate components of normal urine

Abstract The ultrafilterable material of normal human male urine was fractionated by gel filtration on Sephadex G-25 fine (250–400 mesh). At least 6 reproducible anthrone-reacting carbohydrate fractions were obtained. All of them appeared to contain methylpentose and at least five of them seemed to contain uronic acid. The ninhydrin-reacting material showed at least two peaks. Hexosamine analyses have also given at least two maxima.

Isolation and characterization of urinary A and B agglutinogen fractions

Abstract Urinary A and B agglutinogen fractions with high serological activity have been isolated. The presence of glucose was demonstrated in both fractions. In other respects, the chemical composition of A substance material was compatible with a glycoprotein structure similar to that of soluble blood group antigens.

Recovery of the native conformations of the variable and constant halves of an immunoglobulin light chain upon renaturation from the linear random coil state.

Abstract The ability of separated constant and variable light chain halves (obtained by proteolytic digestion of the A.J. lambda light chain) and of the intact light chain to refold into their native conformations after complete reduction and unfolding, has been studied. The renatures proteins were analyzed by gel chromatography, quantitative precipitin curves, optical rotary dispersion, circular dichroism and fluorescence measurements. The results indicate that each half regains its native structure upon renaturation, both when it is free and when it is attached to the other half. The implication of this finding is that during light chain biosynthesis each half folds into its three-dimensional structure independently of the oather half. This is in accord with the idea that the genetic information for the light chain is derived from two separate genes. Preliminary studies of the denaturation of intact light chain by heat and by guanidine hydrochloride have been carried out. Stable intermediates might be expected in such experiments since it is highly probable that the two light chain domains, which independent in other respects, also denature independently. Inspection of the transition curves do not reveal the presence of such intermediates. More accurate analyses, however, are needed to study this problem.