Analysis of immunoreactive and biologically active human parathyroid hormone-peptides by high-performance-liquid-chromatography

Abstract

A combination of high-performance-liquid-chromatography (HPLC), sensitive radioimmunoassays and a homologous in vitro bioassay was used to characterize human parathyroid hormone (hPTH)-peptides in human parathyroid adenoma and plasma. Chromatography of several synthetic hPTH-peptides allows the calibration of the HPLC column. On the basis of sequence hydrophobicity the elution position of peptides can be predicted. A model for the determination of the minimal peptide sequence of each peptide was developed, which based on immunological and physicochemical properties, allows the characterization of unknown hPTH-peptides. Using this technique the heterogeneity of circulating hPTH-peptides in human plasma was examined. Plasma extracts from healthy individuals, osteoporotic, hyperparathyroid and pseudohyperparathyroid patients were investigated. A uniform pattern in the heterogeneity of hPTH-peptides was detected. Using parathyroid adenoma as reference disease specific changes were characterized.