Premium
Structural heterogeneity, post‐translational modifications, and biological activities of SV‐IV, a major protein secreted from the rat seminal vesicle epithelium
Author(s) -
Ferranti Pasquale,
Mamone Gianfranco,
Malorni Antonio,
Guardiola John,
Stiuso Paola,
Metafora Salvatore
Publication year - 1997
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/(sici)1097-0231(19970615)11:9<1007::aid-rcm954>3.0.co;2-o
Subject(s) - chemistry , vesicle , epithelium , microbiology and biotechnology , posttranslational modification , biochemistry , enzyme , membrane , pathology , biology , medicine
The primary structure of purified SV‐IV, a major secretory protein synthesized by the rat seminal vesicle (SV) epithelium, was analysed by electrospray mass spectrometry (ES‐MS). The protein was found to be highly heterogeneous. The various components were separated and identified by reversed phase high‐performance liquid chromatography (HPLC) on line with ES‐MS. Structural characterization of the SV‐IV cyanogen bromide digests revealed the occurrence of a Val/Met substitution in about 50% of the purified protein molecules. We suggest that this mutation is the expression of a genetic polymorphism. Other minor components, corresponding to structural changes (fragmentation, deletion, and phosphorylation) of SV‐IV and probably due to post‐translational modifications of the native protein, were also detected. In particular, by using protein tyrosine phosphatase hydrolysis combined with ES‐MS, we demonstrated that, in the phosphorylated species of SV‐IV, a single phosphate group was covalently bound to the Tyr‐36 residue. The significance of these findings in relation to the regulation of important biological processes, such as immune response, blood coagulation, inflammatory reaction, and mammalian reproduction, are discussed. © 1997 John Wiley & Sons, Ltd.