Involvement of the three inter‐α‐trypsin inhibitor (ITI) heavy chains in each member of the serum ITI family

Abstract

Partial cDNAs coding for each of the three human inter-a-trypsin inhibitor (ITI) heavy chains were expressed in a bacterial plasmid system and rabbits were immunised with the fusion peptides obtained. Despite the strong sequence homology of these chains, the antisera turned out to be highly specific in the analysis of corresponding mRNA translation products or partially digested serum ITI. Besides classical serum ITI members, their use in Western blotting made it possible to evidence an H3-related ITI form and a low-amount HI-related HC/bikunin component. The relative levels of ITI family members was further studied in baboon and foetal calf sera.

Equivalent Involvement of Inter-α-trypsin Inhibitor Heavy Chain Isoforms in Forming Covalent Complexes with Hyaluronan

“…The involvement of the three HC isoforms in each IαI family member has been examined in human, bovine, baboon, and hamster using HC-specific antibodies and the N-terminal peptide sequencing technique [19][20][21][22][23][24][25]. It was reported that human HC isoforms showed different migration rate under proper SDS-PAGE conditions [9,23].…”

Immunolocalization of hyaluronic acid and inter-alpha-trypsin inhibitor in mice

“…Inter-α-trypsin inhibitor (IαI) comprises three genetically different polypeptides: two heavy chains (HC1 and HC2) and one light chain (UTI) (Salier 1990;Salier et al 1993Salier et al , 1996Heron et al 1995). The trypsin inhibitor activity of IαI is localized with UTI.…”

“…The function of follicular fluid in the process of COC expansion is to stabilize the expanding cumulus extracellular matrix, and the factor present in follicular fluid has been identified as proteins of the inter-alpha-trypsin inhibitor (IαI) family (Camaioni et al 1993;Huang et al 1993;Chen et al 1994Chen et al , 1996. IαI is composed of two heavy chains (HC) and one light chain (urinary trypsin inhibitor, UTI) (Salier 1990;Salier et al 1993Salier et al , 1996Heron et al 1995). It has been reported that the IαI HC could act as a structural protein directly cross-linking the secreted HA itself (Huang et al 1993).…”

Proinflammatory cytokines up-regulate synthesis and secretion of urinary trypsin inhibitor in human hepatoma HepG2 cells

“…In hepatocytes, different types of UTI-containing proteins are formed by assembly of UTI with one or two of the three evolutionary related heavy chains (H1, H2, and H3); these proteins comprise inter-␣-inhibitor (I␣I) family members, including I␣I, pre-␣-inhibitor (p␣I), inter-␣-like inhibitor (I␣LI) and free UTI. I␣I, p␣I, and I␣LI are composed of H1+H2+UTI, H3+UTI, and H2+UTI, respectively [4,5]. During inflammation, UTI is cleaved from I␣I family proteins by limited proteolysis in the peripheral circulation or at the inflammation site [6][7][8].…”