ABSTRACT
We have synthesized four kinds of reversed peptides of various physiologically active peptides, which inhibit TNF (tumor necrosis factor) cytotoxicity, produce NGF (nerve growth factor), exert antimicrobial activity and inhibit cell attachment, respectively. They were examined for their biological activity in comparison with that of normal peptides, that is, naturally occurring peptides. The reversed peptides induce similar activities, but to a lesser extent than those of the normal peptides, respectively. These results indicate that there may be conformationally ambiguous binding in some of the naturally occurring ligand-protein interactions. This method may be useful as a tool to rapidly generate a novel lead peptide with the desired biological function from a naturally occurring active peptide.
Subject(s)
Peptides/chemical synthesis , Peptides/pharmacology , Amino Acid Sequence , Animals , Bacteria/drug effects , Cell Line , Cell Survival/drug effects , Cells, Cultured , Mice , Molecular Conformation , Molecular Sequence Data , Nerve Growth Factors/pharmacology , Peptides/chemistry , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/metabolism , Tumor Necrosis Factor-alpha/toxicityABSTRACT
Syntheses and cross-reactivities with progesterone toward the same specific antibody are reported for a series of amides of 11 alpha-hydroxyprogesterone 11-hemisuccinate. Some hypotheses are made regarding the effects of the chemical structure of the substituents on the immunological properties of derivatives.
Subject(s)
Amides/immunology , Antibody Affinity , Hydroxyprogesterones/immunology , Progesterone/analogs & derivatives , Amides/chemical synthesis , Antibody Specificity , Chemical Phenomena , Chemistry , Chromatography/methods , Cross Reactions , Hydroxyprogesterones/chemical synthesis , Progesterone/immunology , Radioimmunoassay , Structure-Activity RelationshipABSTRACT
Synthesis, fluorometric and immunological properties of two new fluorescent derivatives of progesterone are reported. Both compounds were obtained from 11 alpha-hydroxyprogesterone 11-hemisuccinate; the fluorescent molecules were joined to the steroid by bifunctional arms. The first of these is cysteamine whose thiol group was reacted with N-(3-fluoranthenyl) maleimide, and the second is tyramine whose phenolic group was reacted with 1-nitroso-2 naphthol.
Subject(s)
Progesterone/analogs & derivatives , Cross Reactions , Epitopes , Fluorescent Dyes , Immunoassay/methods , Progesterone/analysis , Progesterone/chemical synthesis , Progesterone/immunologyABSTRACT
A fluoroimmunoassay for progesterone is described. It involves a labelled antigen synthesized by linking phenanthroimidazole-2-amine to progesterone-11 alpha-hemisuccinate and specific antiserum (rabbit anti-progesterone-11 alpha-hemisuccinate-bovine serum albumin) with a heterogeneous procedure.
