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Biomedical subjects

R Hansson

Publications and source records attributed to R Hansson.

At least 37 records · Page 2Linked to original sources

Cytochromes P-450 LM3b and LM4 in biosynthesis of bile acids.

Cytochromes P-450 LM3b and LM4 were prepared from untreated and cholestyramine-treated rabbits. The catalytic properties of these cytochrome P-450 fractions towards substrates in bile acid biosynthesis were studied in reconstituted systems containing NADPH -- cytochrome P-450 reductase and phospholipid. Cytochrome P-450 LM3b showed no hydroxylase activity towards cholesterol and only low activity towards some other C27-steroids whereas it catalyzed efficient hydroxylation of testosterone and demethylation of ethylmorphine. Preparations of cytochrome P-450 LM4 catalyzed hydroxylation of cholesterol and other C27-steroids more efficiently than microsomes. Cytochrome b5 had no stimulatory effect on the C27-steroid hydroxylase activities.

Animals↗

Isolation and identification of a trypsin-resistant fragment of human serum albumin with bilirubin- and drug-binding properties.

Extensive digestion of human serum albumin with trypsin at pH 8.8 yields essentially one main fragment which is resistant to further tryptic degradation. The fragment has been characterized by amino acid analysis, N- and C-terminal analyses, cyanogen bromide digestion, electrophoresis, ultracentrifugation and gelfiltration, and circular dichroism measurements. The results indicate that the main fragment consists of the amino acids 182-585. Repeated digestion did not degrade the isolated fragment further. The fragment mainly retains the secondary and tertiary structure of intact human serum albumin as well as its capacity to bind bilirubin and diazepam. The localization of the binding sites for these substances is discussed.

Amino Acids↗