ISOLATION OF HAEMORPHIN-RELATED PEPTIDES FROM FILTER MEMBRANES COLLECTED IN CONNECTION WITH HEMOFILTRATION OF HUMAN-SUBJECTS

This paper describes the extraction and isolation from dialysis filter s of two peptides containing the opioid active sequence haemorphin-7. The filter devices were obtained from uraemic patients subjected to ha emofiltration. Following acidic extraction of the filter membranes the peptides were purified by size-exclusion, ion-exchange chromatography and finally by reversed-phase chromatography using different columns and different chromatographic systems. The purification was guided by radioimmunoassay and the structure of the final products was elucidate d by N-terminal sequencing and fast-atom bombardment-mass spectrometry as well as micro-electrospray mass spectrometry. The isolated peptide s were suggested to be identical to fragments 1-41 and 32-41 of the be ta-chain of human haemoglobin.