AMINO-ACID-SEQUENCE AND TISSUE DISTRIBUTION OF GUINEA-PIG LEUKOTRIENEA(4) HYDROLASE

The guinea-pig leukotriene A(4) hydrolase (LTA(4)H)-encoding cDNA was isolated from a guinea-pig lung cDNA library by cross-hybridization us ing a human probe. The deduced amino acid (aa) sequence consists of 61 1 aa (68 756 Da) and contains all twelve internal peptide and N-termin al sequences determined from the purified enzyme from guinea-pig intes tine. The aa identity of the guinea-pig enzyme with its human, mouse a nd rat counterparts was 92.9, 90.5 and 90.4%, respectively. The previo usly characterized zinc-binding motif and a putative active site were highly conserved, supporting the aminopeptidase activity described for this enzyme. RNA blot analysis demonstrated ubiquitous expression of the LTA(4)H mRNA.