Klinische Wochenschrift

, Volume 66, Issue 17, pp 752–759

Isolation and structural analysis of “Urodilatin”, a new peptide of the cardiodilatin-(ANP)-family, extracted from human urine

  • P. Schulz-Knappe
  • K. Forssmann
  • F. Herbst
  • D. Hock
  • R. Pipkorn
  • W. G. Forssmann
Originalien

DOI: 10.1007/BF01726570

Cite this article as:
Schulz-Knappe, P., Forssmann, K., Herbst, F. et al. Klin Wochenschr (1988) 66: 752. doi:10.1007/BF01726570

Summary

Two major forms of cardiac peptides have been established in the last few years: (a) a prohormone of 126 amino acids (CDD/ANP-1-126) in the endocrine heart and (b) the circulating CDD/ANP-99-126 (=alpha ANP) in blood plasma. The method we applied earlier to isolate the circulating form of cardiodilatin from human blood was used to detect and analyze the biologically active, predominant form of the same polypeptide family excreted by the kidneys. Each step of the isolation procedure was followed up by a bioassay using an in vitro vascular smooth muscle relaxation test and a highly specific RIA against cardiodilatin (CDD-99-126) for the initial purification steps. The polypeptides excreted in 1000 1 of normal human urine were adsorbed to 2.5 kg of alginic acid, and after elution and lyophilization processed on a G-25 Sephadex column. The obtained crude polypeptide fractions were applied to ion-exchange chromatography. Thereafter four steps of HPLC were carried out to purify the polypeptide which was the suggested form of cardiodilatin (CDD) in human urine. The amino acid analysis and gas phase sequence analysis showed that the main form of urinary cardiodilatin is a 32 amino acid residue containing molecule, cardiodilatin-95–126. The molecule is N-terminally extended compared to the circulating CDD-99-126. This suggests that the analyzed urinary peptide is not the residual plasma form, filtrated and renally cleared from blood, but probably a polypeptide produced and processed in the kidney tubules and cleaved by a different postranslational process. Therefore, this vasorelaxant polypeptide is called urodilatin.

Key words

Cardiodilation (CDD) Urodilatin Posttranslational Processing Cardiac Hormones Atrial Natriuretic Polypeptide (ANP) Urine Polypeptide Hormone Amino Acid Sequence 

Abbreviations

ANP

atrial natriuretic polypeptide

CDD

cardiodilatin

HPLC

high performance liquid chromatography

IR

immunoreactivity

mRNA

messenger ribonucleic acid

NA

noradrenaline

OD

optical density

RIA

radio-immunoassay

RP

reversed phase

TFA

trifluoro-acetic acid

Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • P. Schulz-Knappe
    • 1
  • K. Forssmann
    • 1
  • F. Herbst
    • 1
  • D. Hock
    • 1
  • R. Pipkorn
    • 1
  • W. G. Forssmann
    • 1
  1. 1.Institut für Anatomie und Zellbiologie IIIUniversität HeidelbergGermany