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Biomedical subjects

I Lindberg

Publications and source records attributed to I Lindberg.

76 records · Page 5Linked to original sources

A method for the identification and quantitative investigation of denatured proteins in mixtures based on computer comparison of amino-acid patterns.

A procedure is described in which stepwise regression is adapted to permit comparison of the amino-acid pattern from a composite sample with those of simple substances arranged in an easily accessible data bank. The computer program automatically selects from the bank those proteins whose amino-acid patterns best correspond to that of the sample, and calculates the proportion of the proteins contained in the mixture. The procedure is applicable to food analytical problems that involve the identification and determination of proteins in mixtures, and also to situations in which the properties of the proteins have been altered by denaturation or enzymatic degradation. The determination is limited to 3-4 proteins in the mixture.

Amino Acids↗

Multiple immunoreactive forms of met- and leu-enkephalin in fetal and neonatal rat brain and in rat gut.

We have used radioimmunoassays with carboxyl-specific antisera to study the development of met- and leu-enkephalin in rat brain and gut from 13-days of fetal age through adulthood. Fractionation of HCl extracts of fetal and neonatal brain tissues by HPLC revealed the presence of immunoreactive forms other than met- and leu-enkephalin. For example, HPLC separation of extracts of 16-day fetal brain yielded two peaks of leu-enkephalin-like immunoreactivity. One emerged at the position of leu-enkephalin, the other eluted with about one-third the retention time. There were four peaks of met-enkephalin-like immunoreactivity, one with the retention time characteristic of met-enkephalin, the others with shorter retention times. In contrast, all of the met-enkephalin-like immunoreactivity in adult brain eluted with the retention time characteristic of authentic met-enkephalin and all of the leu-enkephalin-like immunoreactivity eluted in the position of authentic leu-enkephalin. Multiple immunoreactive forms of met- and leu-enkephalin were found in extracts of both fetal and adult gut tissues.

Animals↗