A case of an exceptionally high level of urinary-4-hydroxyproline containing polypeptides

Polymorphism of urinary 4-hydroxyproline-containing polypeptides

Using molecular sieve chromatography on Bio-Gel P-2 and then on Bio-Gel P-30, hydroxyproline-containing urinary polypeptides (molecular weight greater than 1500 daltons) were separated into eight fractions. The three main fractions were separated further on phosphocellulose giving seven, nineteen and twelve peaks, respectively, each containing 4-hydroxyproline. Hypotheses about the origin of certain polypeptides are proposed, which take into account the sequence of type I collagen. Among these 38 polypeptides only one shows a quantitative variation in Paget's bone disease and was thus purified. It consists of equal amounts of glycine, proline and 4-hydroxyproline. This particular polypeptide may originate from the N-terminal propeptide of type I collagen.