Separation of histidyl-peptides by thin-layer chromatography and microspectrofluorometric characterization of their o-phthalaldehyde-induced fluorescence

Fluorescence histochemical methods for the study of peptide hormone-producing cells

Fluorescence histochemical methods for the demonstration of specific residues in peptides and proteins are reviewed: Formaldehyde-ozone for NH2-terminal tryptophan, formaldehyde-HCl for tryptophan regardless of position in the peptide, OPT for NH2-terminal histidine, formaldehyde-fluorescamine for "protected" amino groups, nitroso-naphthol for tyrosine, and phenanthrenequinone for arginine residues. The methods are potent in demonstrating granule-stored material in peptide hormone-producing cells. Also quinacrine, the fluorescent anti-malaria agent, binds to granular components, as yet unidentified, in several endocrine cell types. In many cases the fluorescence histochemical methods seem to demonstrate peptides and proteins distinct from the known hormones.

Thin-layer chromatography of histidine, histamine and histidyl peptides at picomole level using a unique fluorogenic reaction with fluorescamine

A thin-layer chromatography procedure has been devised for detecting histidine, histamine, histidyl peptides and related imidazole compounds; it is based on a unique fluorogenic reaction, in which the compounds are derivatized with fluorescamine, converted into different fluorescent products by heating in strong acid medium, and separated on silica gel plates with an appropriate solvent system. As little as 4 to 60 pmole of the histidine derivative could be detected under long-wave (366 nm) ultraviolet radiation. Other classes of compounds gave no fluorescent spots.

Improved technique for the analysis of amino acids and related compounds on thin layers of cellulose.XI. Direct, visual micro-method for investigating the primary structural sequence of collagen and other proteins

The present paper describes a new variation of the "finger printing" technique for examining the primary structure of proteins. It is based on the production of a reproducible, partial acid hydrolysate consisting of amino acids and small peptides which are separated into compact spots by bi-dimensional thin-layer chromatography. The spots are characterized by ther Rf values and colour reactions with a variety of reagents. The method was initially developed for collagen but has been applied to other proteins, with interesting results. It has developed logically from earlier, systematic studies on amino acids and peptides, and holds promise for the comparative investigation of normal and diseased human collagen.