Isolation of beta2-microglobulin from human colostrum (author's transl)]

The beta2-microglobulin from human colostrum was purified by a combination of ordinary protein-chemical techniques: gel filtration, ion-exchange chromatography and zone electrophoresis. The procedure is organized in such a way that the simultaneous isolation of many other milk proteins is possible. The beta2-microglobulin obtained from colostrum cannot be distinguished by physical-chemical or immunological means from the beta2-microblobulin isolated from the urine of patients with kidney-tubule diseases. At the beginning of lactation, human milk contains significantly more than 10 mg/-100 ml beta2-microglobulin, but the concentration drops within two or three days to 15-30% of the original amount.     

Isolation and characterization of 7S-beta1-globuline from human erythrocytes (author's transl)]

A new protein was isolated from lysates of washed human erythrocytes in a two step procedure using ionexchange chromatography and gel filtration. The protein has the electrophoretic mobility of a beta1-globulin. On ultracentrifugation the purified protein when dissolved in a 0.05 M phosphate buffer (pH 6.8), containing 0.2 M NaCl sediments with 6.88 S and shows a molecular weight of 150,000-180,000 daltons. In salt solutions with higher ionic strength the molecules dissociate reversibly into subunits which have a molecular weight of 40,000-45,000 daltons. The 7S-beta1-erythrocyte protein according to its behavior at ultracentrifugation, gel filtration and SDS poly-acrylamide gel electrophreses apparently is composed of 4 identical or similar subunits which are loosely held together by noncovalent bonds. Chemically the 7S-beta1-erythrocyte protein consists of 99% amino acids and 1% carbohydrates. The concentration of this protein in erythrocytes amounts to 250 mg per 100 ml packed red blood cells. The protein is not found in the membrane. In its physical, chemical and immunochemical properties the 7S-beta1-erythrocyte protein differs from all other well defined proteins and enzymes from human red cells thus far known.     

Isolation and separation of nucleic acids from Streptomyces hydrogenans (author's transl)]

Different methods for homogenization of cells of Streptomyces hydrogenans, for extraction of nucleic acids and for fractionation of the RNA and DNA obtained were critically examined. The only way to prepare high molecular weight rapidly labelled RNA and polysomes was to grind freeze-dried cells together with kieselguhr with a mortar and pestle. The best results for extraction of nucleic acids from the cell homogenate were obtained in the presence of diethyl pyrocarbonate (diethyl oxydiformate), yielding nucleic acids of considerable purity in a minimal amount of time. The best resolution of extracted nucleic acids was achieved by electrophoresis in 2% agarose acrylamide gels. This technique proved that during the cell homogenization and extraction procedure the bulk of nucliec acids was not degraded to low molecular weight material. An improved device for the registration of the profile of the absorption after gel electrophoresis is described.     

Purification and characterization of the free secretory piece of human colostrum (author's transl)]

The free secretory piece is isolated from human colostrum by gel filtration and ion-exchange chromatography in high yield (200 mg/l colostrum). DEAE-Cellulose chromatography separates the free secretory piece in two fractions which are electrophoretically distinct, but otherwise have the same characteristics, like molecular weight, antigenic determinants, N-terminal sequence, peptide map and amino acid composition. It was therefore concluded that the protein part of the secretory piece is homogenous.     

Hydrolytic conditions of the conjugated steroids from human urine (author's transl)]

The hydrolisis of dehydroepiandrosterone sulfate added to human urine was studied under several hydrolytic procedures. Enzymatic and acid hydrolysis with and without the previous removal of enzymic inhibitors present in the human urine were compared. The simple precipitation of inorganic ions with barium acetate before the enzymatic hydrolysis was considered an efficient procedure giving an 81% recovery of the added dehydroepiandrosterone. Since this procedure does not involve rearrangements in the steroid molecules, and because of its simplicity it is considered adequate for the determination of the urinary steroid excretion patterns in humans allowing the quantitation of some conjugates (16 alpha-hydroxy-dehydroepiandrosterone) otherwise not detectable because of its incomplete hydrolysis and extraction.