Characterizing molecular heterogeneity of gastrin-releasing peptide and related peptides

Abstract

Publisher Summary The characterization of multiple gastrin-releasing peptide molecular variants, and gene-related peptides, has been achieved utilizing region specific radioimmunoassays and high-resolution purification techniques. The posttranslational processing sites that yield these various forms are double basic residues and several other types of bonds. For example, processing occurs after second position prolines at the amino terminus, at single basic residues, and between aspartic and serine residues. Co-injections of similar amounts of synthetic and natural peptide should be done to avoid false conclusions about elution positions caused by variability in pump speed, chart recorder speed, or gradient formation. The various forms of gastrin-releasing peptide are well separated in several different chromatography systems. A combination of more than one separation technique is suggested to validate any conclusions about molecular forms based on immunoreactivity coeluting with standard peptides.