Purification and characterization of α1-proteinase inhibitor and antithrombin III: major serpins of rainbow trout (Oncorhynchuss mykiss) and carp (Cyprinus carpio) blood plasma

Abstract

The main serine proteinase inhibitors of rainbow trout (Oncorhynchuss mykiss) and common carp (Cyprinus carpio) blood plasma were isolated and purified. The investigated inhibitors, alpha(1)-proteinase inhibitor (alpha(1)-PI) and antithrombin III (AT III), act by forming stable complexes with target proteinases. The association rate constants k (on) for the interaction of fish plasma inhibitors with several serine proteinases have been determined: k (on) for both carp and rainbow trout alpha(1)-PI were >10(7) M(-1) s(-1) for human neutrophil elastase, and in the case of bovine trypsin and chymotrypsin k (on) values were 2.0-5.2 x 10(6) M(-1) s(-1). Association rate constants k (on) for the interaction of carp and rainbow trout AT III with bovine trypsin and thrombin were about 1.3 x 10(4)-7.9 x 10(5) M(-1) s(-1) without and >10(7) M(-1) s(-1) in presence of heparin; so antithrombins require the presence of heparin to become effective proteinase inhibitors. The high degree of homology of the estimated amino acid sequences of fish inhibitors reactive site loops confirms their similarity with other proteinase inhibitors from the serpin family.

Amblyomma americanum tick saliva serine protease inhibitor 6 is a cross‐class inhibitor of serine proteases and papain‐like cysteine proteases that delays plasma clotting and inhibits platelet aggregation

“…Thus, the observation in the present study that r Aam S6, which has a neutral aa residue ‘Ser’ at the P1 site (Mulenga et al ., ), inhibited both trypsin and chymotrypsin is interesting though not unusual. Similar observations were reported for other serpins such as rainbow trout ( Oncorhynchuss mykiss ) and common carp ( Cyprinus carpio ) α1‐antiprotease inhibitor 1 (Mickowska, ) that also have polar neutral ‘Met’ at the P1 site. The apparent consistency of findings in the present study with other studies provides a measure of confidence in our data.…”

Molecular cloning, genomic structure, polymorphism analysis and recombinant expression of a α1-antitrypsin like gene from swamp eel, Monopterus albus

“…Increased literatures reports that AAT-like proteins from seminal plasma, blood plasma, muscle, and serum of various fish exhibited similar biochemical characteristics [16][17][18][19]. Ayu AAT transcripts were present in a variety of tissues, with the highest level in the liver [12].…”

“…Although cDNA sequences encoding the ayu [12], carp [13], rainbow trout [14], and zebrafish [15] AATs have been documented, little reporting of the genomic structure of fish AAT can be found. Most studies have focused on the anti-proteinase characterizations of AAT, with few results shown on teleost immunological or anti-inflammatory functions [13,[16][17][18][19]. During the acute phase response, ayu AAT expression was significantly up-regulated at the mRNA and protein level [12], but expression in Atlantic cod [20] and rainbow trout [21] were found to be down-regulated.…”