IMMUNOCHEMICAL AND FUNCTIONAL-PROPERTIES OF BILIARY ALPHA-1-ANTITRYPSIN

Citation
S. Janciauskiene et al., IMMUNOCHEMICAL AND FUNCTIONAL-PROPERTIES OF BILIARY ALPHA-1-ANTITRYPSIN, Scandinavian journal of clinical & laboratory investigation, 56(7), 1996, pp. 597-608
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Medicine, Research & Experimental
ISSN journal
0036-5513
Volume
56
Issue
7
Year of publication
1996
Pages
597 - 608
Database
ISI
SICI code
0036-5513(1996)56:7<597:IAFOBA>2.0.ZU;2-G
Abstract
Alpha-1-antitrypsin (AAT), the archetype of the serpin (serine protein ase inhibitor) superfamily, is synthesized by hepatocytes and excreted to some extent into bile. The role of intact biliary AAT in gallstone pathogenesis is unsettled, but its 36-residue C-terminal peptide was found to promote cholesterol crystallization in a bile model. The pres ent study showed biliary AAT to have specific properties that differ f rom serum AAT regarding immunoreactivity, heat stability and anti-prot eolytical activity. Electrophoretical and immunochemical methods were used to characterize biliary AAT. The level of its inhibitory activity was determined spectrophotometrically. In 18 samples from common bile duct and 12 samples from gallbladder bile, AAT was found to be heat-s table and functionally inactive. Added to the untreated, temperature-i nactivated or protease inhibitors containing bile, native AAT became f unctionally inactive, heat-stable and lost its immunoreactivity. In co ntrast, heat-inactivated AAT, native albumin, transferrin, alpha-1-ant ichymotrypsin and IgG were unaffected on being added to bile. AAT in h uman bile manifests specific biochemical properties, such as functiona l inactivity and heat stability, that may be consistent with a conform ational transition of the serpin molecule induced by the hydrophobic e nvironment, and which must be considered when evaluating its role in g allstone pathogenesis.