Protein A and acid alpha-1-glycoprotein as factors discriminating immunoglobulins G in children suffering from leukemias.

The studies on IgG-3 subclass in the course of acute lymphoblastic leukemia (ALL) in children were performed. The presence of this IgG subclass was not shown, using chromatography on AGP-Sepharose for its isolation and Protein A-Sepharose for its identification. The possibilities of excretion of this IgG subclass with urine and proteolytic digestion in neutral pH by serum enzymes were excluded.

Complexes of acid alpha 1-glycoprotein with immunoglobulins G in normal human blood serum.

DEAE-cellulose chromatography was applied for isolation of the complexes of acid alpha 1-glycoprotein (alpha 1-AGP) with immunoglobulins G (IgG). The heterogeneous glycoprotein fraction V was found to contain 75% of total alpha 1-AGP complexed with IgG3, as identified by Protein A-Sepharose chromatography. The results obtained indicate that in normal blood serum 30% of IgG3 and 75% of alpha 1-AGP are bound in the IgG3 - alpha 1-AGP complexes, whereas the remaining parts of IgG3 and alpha 1-AGP are present in free form.

Interaction of DNA with guanidylated BPTI.

It was shown that guanidylated BPTI complexed with DNA stablized the native structure of the latter. It was found that hyperchromism values of DNA-guanidylated BPTI complexes, dialyzed against increasing and redialized against decreasing concentrations of NaCl or urea, amount ot ca 50% of hyperchromism values of free DNA or nondialyzed complexes. All three geometric forms of DNA were detected in DNA-guanidylated BPTI complexes subjected to the transient action of NaCl or urea.

The influence of dimethylsulfoxide on level of serum sialoproteins in rats.

Intraperitoneal injection of DMSO in rats significantly lowered level of serum sialoproteins and caused appearance of seromucoid fractions devoid of NANA (asialoproteins). The influence of DMSO on sialoprotein metabolism in the liver is discussed.

Heterospecific activity of rat interferon.

In the experiments performed in vitro and in vivo it has been found that the rat and rat embryo fibroblasts cultured in vitro after the induction with virus produce interferon which displays the antiviral activity not only in the homologous cells but also in the heterologous ones. When analysed by chromatography on Sephadex G-100 it was shown that the rat serum contains two interferon populations differing in the molecular weight and both active in the homologous and heterologous cells. The interferon with the heterospecific activity has been used in the experimental therapy of mice infected with Encephalomyocarditis Virus (EMC), Vesicular Stomatitis Virus (VSV) and Influenza Virus, and was found to be effective.

Rat interferons. IV. Sialoproteins in rat serum.

Introduction of virus as inductor of interferon into rats caused a decline in serum levels of sialic acid in blood taken at the time of maximum interferon activity. Differences in the acute phase proteins were dependent on the type of virus used for induction. NDV injected intravenously did not lower serum levels of seromucoid, but given together with DMSO markedly depressed the content of this protein in the serum.

Partial purification of nucleopeptides from rabbit skeletal muscle by the tannin-caffeine procedure.

After precipitation of acid-soluble proteins from sulfosalicylic acid extracts of rabbit skeletal muscles with tannin at neutral pH, the remaining material still formed insoluble complexes with tannin. After removing tannin with caffeine complexes subjected to column chromatography on Dowex 1 x 8 gave four fractions containing both amino acids and nucleotides. It was concluded that the isolated material contains nucleopeptides, besides nucleotides.

The use of gel-filtration for the isolation of pure nisin from commercial products.

Commercial nisin was fractionated using a Bio-Gel P-10 column and ion-exchange chromatography on CM-sephadex C-25. Pure nisin having a titre of 40 X 10(6) units per gram was obtained. In polyacrylamide-gel electrophoresis the pure nisin gave three bands.

Trypsin inhibitors in bovine lung and pancreas during development.

1. The activity of trypsin inhibitors in lung and pancreas increased with age of the animals. 2.