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Biomedical subjects

J Izdebski

Publications and source records attributed to J Izdebski.

32 records · Page 2Linked to original sources
PubMed1982

Synthesis and properties of human gamma-lipotropin.

The synthesis of human gamma-lipotropin by the solid-phase method is described. The synthetic product was characterized by Rf in partition chromatography on Sephadex G-50, paper electrophoresis, polyacrylamide gel electrophoresis, thin-layer chromatography, HPLC, end group determination, peptide mapping of a tryptic digest, and amino acid analyses of acid and enzymic digests. The synthetic material is identical to natural human gamma-lipotropin when assayed against natural human beta-lipotropin for lipolytic activity.

Amino Acid Sequence↗
PubMedDate not supplied

Evaluation of carbodiimides using a competition method.

A competitive reaction of activated Boc-Ala-OH and Boc-Phe-OH with H-Leu-resin has been developed for assessing the relative efficiencies of different carbodiimides. This allowed a comparison of the efficiency of the carbodiimides N,N'-dicyclohexylcarbodiimide,N,N'-diisopropylcarbodiimide, N-tert-butyl-N'-methylcarbodiimide and N-tert-butyl-N'-ethylcarbodiimide. Comparable results were obtained when these reagents were used for the preformation of symmetrical anhydrides or of 1-hydroxybenzotriazole esters in situ. Differential incorporation was observed when asymmetrical carbodiimides were used for peptide bond formation by the direct carbodiimide procedure.

Alanine↗
PubMedDate not supplied

Synthesis of a novel side-chain to side-chain cyclized enkephalin analogue containing a carbonyl bridge.

A novel type of cyclic opioid peptide analogue, cyclo[N epsilon,N epsilon'-carbonyl-D-Lys2,Lys5]enkephalinamide, was prepared from a linear precursor peptide. The peptide was synthesized on the Merrified resin and also by a combination of the solid-phase technique and the classical method in solution. In both cases the cyclization was performed by reaction of bis(4-nitrophenyl)carbonate with the free side-chain amino groups of the two lysine residues. The described method permits the convenient preparation of novel peptide analogues cyclized via a ureido group incorporating the side-chain amino groups of two alpha, omega-diamino acid residues. The cyclic enkephalin analogue containing a 21-membered ring structure showed preference for mu over delta opioid receptors in opioid bioassays in vitro.

Animals↗