Human inter-alpha-trypsin inhibitor. Synthesis and maturation in hepatoma HepG2 cells.
In hepatoma HepG2 cells, human inter-alpha-trypsin inhibitor (ITI) was synthesized as three heavy chains, H-1 (100 kDa), H-2 (110 kDa) and H-3 (113 kDa), and light hybrid chain (49.5 kDa) composed of alpha 1-microglobulin and HI-30 (ITI derivative, human inhibitor of 30 kDa). The association of at least two heavy chains, H-1 and H-3, with the HI-30 part of the light chain gave rise to a molecule similar to serum ITI. A composite protein (approximately 250 kDa) including heavy and light chains was also secreted, while alpha 1-microglobulin and ITI H-2 protein were released as separate entities. Light chain synthesis could be the limiting factor for ITI maturation.
Bourguignon
J
J
INSERM Unité 295-Faculté de Médecine-Pharmacie de Rouen, Saint-Etienne-du-Rouvray, France.
Sesboüé
R
R
Diarra-Mehrpour
M
M
Daveau
M
M
Martin
J P
JP
D000510:Alpha-Globulins / Q000096:biosynthesis* / Q000276:immunology; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D008113:Liver Neoplasms / Q000378:metabolism*; D011233:Precipitin Tests; D014361:Trypsin Inhibitors / Q000096:biosynthesis* / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000378:metabolism
D000510:Alpha-Globulins; D007106:Immune Sera; D014361:Trypsin Inhibitors; C011877:inter-alpha-inhibitor