title: Identification of hydrophobic fragments of alpha 1-antitrypsin and C1 protease inhibitor in human bile, plasma and spleen.
abstract: Hydrophobic peptides were isolated from the phospholipid fraction of human bile, plasma and spleen by exclusion chromatography in organic solvents. From plasma, the activation peptide of C1 protease inhibitor was recovered, from spleen the activation peptide of alpha 1-antitrypsin, and from bile, both these peptides, as well as a fragment generated by proteolytic cleavage of alpha 1-antitrypsin six residues N-terminal of the P1-P1' peptide bond. Cleavages in this region inactivate antiproteases but have previously not been reported to occur in vivo. These peptides in human bile may reflect physiological actions in regulation of antiproteolytic activity or bile secretion processes, and/or be of importance for the physicochemical state of cholesterol, phospholipids and bile acids in bile.
authors.affiliation: Department of Chemistry I, Karolinska Institutet, Stockholm, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Johansson
authors.forename: S
authors.initials: S
authors.lastname: Gröndal
authors.forename: J
authors.initials: J
authors.lastname: Sjövall
authors.forename: H
authors.initials: H
authors.lastname: Jörnvall
authors.forename: T
authors.initials: T
authors.lastname: Curstedt
mesh_terms: D001646:Bile / Q000737:chemistry*; D002850:Chromatography, Gel; D003174:Complement C1 Inactivator Proteins / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D010446:Peptide Fragments / Q000302:isolation & purification*; D013154:Spleen / Q000737:chemistry*; D000515:alpha 1-Antitrypsin / Q000378:metabolism*
chemical_list: D003174:Complement C1 Inactivator Proteins; D010446:Peptide Fragments; D000515:alpha 1-Antitrypsin