CDNA SEQUENCE AND DEDUCED AMINO-ACID-SEQUENCE OF BOVINE OVIDUCTAL FLUID CATALASE

A bovine oviductal fluid catalase (OFC) which preferentially binds to the acrosome surface of some mammalian spermatozoa has recently been p urified. The objectives of this study were to clone the OFC, obtain th e full-length cDNA and protein sequence and determine which characteri stics of the proteins are associated with the binding of the enzyme to sperm surface. Northern blot analysis revealed low levels of catalase mRNA in bovine oviducts and uterus compared to the liver and kidney. Screening of a cDNA library from the cow oviduct permit to obtain a fu ll-length cDNA of 2282 bp, with an open reading frame of 1581 bp codin g for a deduced protein of 526 amino acids (59 789 Da). The deduced pr otein contained four potential N-glycosylation sites and many potentia l O-glycosylation sites. The OFC protein exhibited high identity with catalase from other bovine tissues, like-wise with catalases from huma n fibroblast and kidney, and with rat liver catalase. The homology of amino acid sequence of OFC with bovine liver catalase was about 99%. H owever the OFC posses an extended carboxyl terminus of 20 amino acids not present on the liver catalase. This result is supported by a lower mobility of the OFC compared to the liver catalase when both proteins are submitted on SDS-PAGE. (C) 1998 Wiley-Liss, Inc.