Cervico-Vaginal mucus proteins of buffalo

Cervico-vaginal fluid (CVF) plays significant roles in coitus, sperm transport and implantation. It is believed to be a good non-invasive biomarker for various diagnostic purposes. In this study, a comprehensive proteomic analysis of buffalo CVF was performed during the estrous cycle in order to document the protein expressions, utilizing SDS-PAGE, mass spectrometry, and immunoblot.Xcalibur software (version 2.0. SR1) was used for analyzing the mass spectrometry data. Product ion scans gathered from tandem mass spectrometry were involved in the database search software SEQUEST (TURBO) (http://sjsupport.thermofinnigan.com/project/product_support/xcal_layered_apps_turbosequest.htm). Peak lists were created from the products in the scan data (threshold set to 10,000) and these were searched against the mammalian protein sequence database from NCBI (http://www.ncbi.nlm.nih.gov/). Modification of cysteine by carboxymethylation and methionine by oxidation modifications was allowed. The mass tolerance for the precursor peptide ions was set to 3.5 and the fragment ion tolerance was set to 1. Singly charged, doubly charged and triply charged peptides have higher cross-correlation score viz., 1.9, 2.2 and 3.75, respectively, which give high confidence in terms of protein identification. More than two unique peptides for each protein were taken for confirmation of the protein present in the sample.