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Biomedical subjects

I Banga

Publications and source records attributed to I Banga.

At least 19 recordsLinked to original sources
PubMed1985

Is elastomucoproteinase a double-headed enzyme?

During isolation pancreatic elastase is accompanied by a minor component, elastomucoproteinase (EMPase), which can be separated in pure state by anion-exchange chromatography. EMPase exhibits both proteolytic and mucolytic activities. Applying powdered aortic preparations as a substrate, the enzyme can split off carbohydrate moieties, but it can also cleave peptide bonds as a proteinase. Assaying with tripeptide-p-nitroanilide substrates, the enzyme can decompose only those substrates which contain Phe or Tyr at the C-terminal. It appeared that the binding of Bz-Ala-Gly-Phe-pNA was the best, while the hydrolysis of Bz-Ala-Pro-Tyr-pNA was the fastest. Proteolytic activity of EMPase can be completely inhibited with phenylmethanesulphonyl fluoride, whereas its mucolytic activity only by 20%. The two activities may be located at two separate sites. The enzyme seemed to be composed of a single polypeptide chain by SDS-gel electrophoresis in the presence of urea and beta-mercapto-ethanol.

Amidohydrolases↗
PubMed1980

[Lipoprotein examination in old hyperlipemic persons (author's transl)].

The fluorescence and thiobarbituric acid reaction of isolated beta lipoprotein (beta-LP) and alpha lipoprotein (alpha-LP) have been studied in young, old, and old hyperlipemic persons. Specific fluorescence showed no significant difference in the beta-LP of young and old individuals. However, the difference was signficant in the A:F 380:450 fluorescence (A= activation wavelength, F = fluorescence or emission wavelength) of the alpha-LP. On the effect of autooxidation the alpha-LP showed a significant increase in both the A:F 380:450 and the A:F 410:470 fluorescence. Absorption at 530 nm has been studied by the thiobarbituric acid (TBA) reaction. The malondialdehyde (MDA) content has been given as microgram/mg on the basis of the curve obtained by the known quantity of MDA. The MDA content of beta-LP in the young and old groups was less increased as compared to the substantial increase of alpha-LP. As opposed to results obtained in senile persons MDA increase of alpha-LP has been significant in old hyperlipemic individuals. In addition to the absorption peak at 530 nm, characteristic for MDA, a peak at 450 nm has been obtained by TBA. A yellow-brown substance associated with hyperlipemia did appear mainly in the protein fraction isolated from alpha-LP and has been named protein III. During oxidation in hydrochloric acid a yellow-brown substance appeared from protein III fraction and became unsoluble and dark brown in hyperlipemic persons. The substance was considered as a precursor of the atherofluorescent component (AFC) present in atherosclerotic aortas. The reaction in the alpha-LP, and particularly in its protein component, with MDA (originating from peroxidezed unsaturated fatty acids) leads to complexes which are, assumably, precursors of atheromatous lipid and calcium plaques.

Adolescent↗