Profiling proteomic responses of Staphylococcus aureus exposed to colostrum hexasaccharide (CHS) through label-free mass spectrometric profiling

To resolve the problem of antibiotic resistant, there is an extensive approach being tried to find natural molecules which protects against pathogen invasion. In this present study we scrutinize CHS effects on protein expression in S. aureus. Colostrum Hexasaccharide (CHS) was collected and purified from Female mares (Equus caballus). Working concentration of CHS were evaluated for its activity on the growth of ATCC S aureus 25923. The ATCC 25923 S. aureus sensitivity towards CHS was determined by MIC test as per guidelines of the CLSI, USA. The proteomic profiling of S. aureus proteins was obtained after the treatment of CHS (at IC value) with comparison to untreated control with the usage of in-solution digestion following the LC-MS/MS analysis. Identification and differential expression profile for targets and sequence of the protein were obtained through MASCOT, Swiss-Prot, and TrEMBL search engines and label-free quantification (Progenesis QI). The growing turbidity of S. aureus was reduced over the time in concentration dependent manner. The IC50 concentration value was quite high and it was more than 5mg/ml. CHS influenced around 30 proteins in comparative proteomics analysis. Five proteins named DNA-binding protein HU, MarR family transcriptional regulator, 40S ribosomal protein L7/L12, 3-hexulose-6-phosphate synthase and general stress protein were significantly (Based on ANOVA value (>0.05; p value) differentially expressed. Based on fold changes elongation factor Ts, Coagulase, and multiple resistance and pH adaptation (Mrp)-like protein considered to be expressed differentially. In this study we report the protein targets of CHS of clolostrum to that in S aureus pathogen on which is able to attenuate the growth of S aureus and may play an effective antipathogenic novel molecule to serve as the lead compound.