Screening and validation of an alkaline-tolerant biomimetic affinity chromatography A5-87 resin for purification of discarded bovine serum Immunoglobulin G

It is important to recycle the bovine blood discarded at slaughter and develop it into high value-added bovine serum products. Biomimetic affinity chromatography (BiAC) resins have been developed to specifically purify bovine serum immunoglobulin G (Bs-IgG). The BiAC strategy was used to screen the resins with the best purification effect on Bs-IgG. Four resins with specificity for Bs-IgG adsorption were selected from 90 BiAC resins. Finally, BiAC-A5-87 was selected and used to purify Bs-IgG based on the results of SDS-PAGE and BCA protein quantification analysis. The adsorption capacity and purity of BiAC-A5-87 were 32.79 ± 3.57 mg/mL and 85.9 ± 1.21 % for Bs-IgG, respectively. The total protein recovery rate of Bs-IgG purified by BiAC-A5-87 was 89.78±3.52 %. The resin of BiAC-A5-87 column was recycled in 40 breakthrough cycles, and its Bs-IgG adsorption efficiency decreased by less than 10 %. After soaking BiAC-A5-87 in 1.0 moL NaOH solution for 64 h, its adsorption capacity for Bs-IgG was almost the same as that before soaking. The development of waste bovine serum not only realizes the utilization of blood resources and produces high economic benefits but also reduces the pollution of the environment.

tuberculosis using biomimetic affinity chromatography coupled with LC-MS/MS analysis

M. tuberculosis is the most successful intracellular pathogen and remains a major threat to human health. It is crucial to investigate the profile of cytoplasmic proteins from M. tuberculosis for pathogenesis, clinical markers, and protein vaccine development. In this study, six biomimetic affinity chromatography (BiAC) resins with high differences were selected for M. tuberculosis-cytoplasmic protein fractionation. All fractions were identified using liquid chromatography-mass spectrometry (LC-MS/MS) analysis. A total of 1246 M. tuberculosis proteins were detected (p < 0.05), among which 1092 M. tuberculosis proteins were identified in BiAC fractionations and 714 M. tuberculosis proteins in un-fractionations (Table S1.3.1). The majority of 66.8% (831/1246) identifications were distributed in the range of Mw 7.0-70.0 kDa, pI 3.5-8.0, and Gravy values <0.3. Furthermore, 560 M. tuberculosis proteins were detected in both the BiAC fractionations and un-fractionations. Compared with the un-fractionations, the average number of prot_matches, prot_cover, prot_sequence, and emPAI values of these 560 proteins in the BiAC fractionations were increased by 3.791, 1.420, 1.307, and 1.788 times, respectively. Overall, compared with un-fractionations, the confidence and profile of M. tuberculosis cytoplasmic proteins were improved by BiAC fractionations coupled with LC-MS/MS analysis. The strategy of BiAC fractionation can be used as an effective method for pre-separating protein mixtures in proteomic studies.

Improving basic and membrane protein MS detection of the culture filtrate proteins from Mycobacterium tuberculosis H37Rv by biomimetic affinity prefractionation

The culture filtrate proteins (CFPs) from Mycobacterium tuberculosis have been shown to induce protective immune responses in human and animal models, making them a promising source of candidate targets for tuberculosis drugs, vaccines, and diagnostics. The constituents of the M. tuberculosis CFP proteome are complex and vary with growth conditions. To effectively profile CFPs, gel-based prefractionation is usually performed before MS analysis. In this study, we describe a novel prefractionation approach by which the proteome is divided into seven partially overlapping fractions by biomimetic affinity chromatography (BiAC) using a six-column cascade. The LC-MS/MS analysis of individual fractions identified a total of 541 CFPs, including 61 first-time identifications. Notably, ∼1/3 (20/61) of these novel CFPs are membrane proteins, among which nine proteins have 2-14 transmembrane domains. In addition, ∼1/4 (14/61) of the CFPs are basic proteins with pI values greater than 9.0. Our data demonstrate that biomimetic affinity chromatography prefractionation markedly improves protein detection by LC-MS/MS, and the coverage of basic and hydrophobic proteins in particular is remarkably increased.