Elafin and its precursor, trappin-2 or pre-elafin, are specific endogenous inhibitors of human neutrophil elastase and proteinase 3 but not of cathepsin G. Both inhibitors belong, together with secretory leukocyte protease inhibitor, to the chelonianin family of canonical protease inhibitors of serine proteases. A cDNA coding either elafin or its precursor, trappin-2, was fused in frame with yeast a-factor cDNA and expressed in the Pichia pastoris yeast expression system. Fulllength elafin or full-length trappin-2 were secreted into the culture medium with high yield, indicating correct processing of the fusion proteins by the yeast KEX2 signal peptidase. Both recombinant inhibitors were purified to homogeneity from concentrated culture medium by one-step cationic exchange chromatography and characterized by N-terminal amino acid sequencing, Western blot and kinetic studies. Both recombinant elafin and trappin-2 were found to be fastacting inhibitors of pancreatic elastase, neutrophil elastase and proteinase 3 with k ass values of 2-4 · 10 6 M )1

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Hemocyanin is present as 2 subunits in the hemolymph of Penaeus vannamei. Isolated from a hepatopancreas cDNA library of this penaeid shrimp, the cDNA chain (2095 bp) corresponds to a full length hemocyanin messenger as determined by Northern hybridization, with a short 5' untranslated region (17 bp), an open reading frame (1989 bp counting initiation and termination codons) coding for a signal peptide (13 residues) and a mature hemocyanin (648 amino acids), and a 3' untranslated region (89 bp) followed by the polyadenylated track. It is the first time that the existence of a hydrophobic signal peptide is shown in arthropod hemocyanin. Two primary N-terminal sequences are determined and a 3-fold increase of mRNA content, measured in the hepatopancreas during the premoult stages, is reported. The low level of polymorphism shown by P. vannamei hemocyanin, along with its weak percentage identity with counterparts and its similarity with hemocyanin from Panulirus intermptus, suggests that this arthropod hemocyanin may be a primitive subunit that has evolved independently, following gene duplication.

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