Progress in proteomics research has led to a demand for powerful analytical tools with high separation efficiency and sensitivity for confident identification and quantification of proteins, posttranslational modifications, and protein complexes expressed in cells and tissues. This demand has significantly increased interest in capillary electrophoresis‐mass spectrometry (CE‐MS) in the past few years. This review provides highlights of recent advances in CE‐MS for proteomics research, including a short introduction to top‐down mass spectrometry and native mass spectrometry (native MS), as well as a detailed overview of CE methods. Both the potential and limitations of these methods for the analysis of proteins and peptides in synthetic and biological samples and the challenges of CE methods are discussed, along with perspectives about the future direction of CE‐MS. @ 2019 Wiley Periodicals, Inc. Mass Spec Rev 00:1–16, 2019.

The present study investigated the seminal plasma proteome of Holstein bulls with low (LF; n = 6) and high (HF; n = 8) sperm freezability. The percentage of viable frozen-thawed sperm (%ViableSperm) determined by flow cytometry varied from-2.2 in LF to + 7.8 in HF bulls, as compared to the average %ViableSperm (54.7%) measured in an 860-sire population. Seminal proteins were analyzed by label free mass spectrometry, with the support of statistical and bioinformatics analyses. this approach identified 1,445 proteins, associated with protein folding, cell-cell adhesion, NADH dehydrogenase activity, ATP-binding, proteasome complex, among other processes. There were 338 seminal proteins differentially expressed (p < 0.05) in LF and HF bulls. Based on multivariate analysis, BSP5 and seminal ribonuclease defined the HF phenotype, while spermadhesin-1, gelsolin, tubulins, glyceraldehyde-3-phosphate dehydrogenase, calmodulin, ATP synthase, sperm equatorial segment protein 1, peroxiredoxin-5, secretoglobin family 1D and glucose-6-phosphate isomerase characterized the LF phenotype. Regression models indicated that %ViableSperm of bulls was related to seminal plasma peroxiredoxin-5, spermadhesin-1 and the spermadhesin-1 × BSP5 interaction (R 2 = 0.84 and 0.79; p < 0.05). This report is the largest dataset of bovine seminal plasma proteins. Specific proteins of the non-cellular microenvironment of semen are potential markers of sperm cryotolerance. Sperm cryopreservation, artificial insemination (AI) and in vitro fertilization followed by embryo transfer are among the most used assisted reproductive technologies (ARTs), allowing genetic selection of farm animals 1 , conservation of wild and endangered species 2 , successful pregnancies for infertile couples 3 and preservation of fertility in cancer patients 4. Successful implementation of ARTs depends on cost-effective and efficient cryopreservation of sperm cells. Cryopreservation protocols include the dilution of fresh semen with extender containing cryoprotectants, buffers and antibiotics, followed by freezing in liquid nitrogen. Freezing and thawing semen interferes with the structure of the sperm membranes, alters functions of membrane proteins and ion channels, causes premature capacitation and acrosome reaction and yields excessive reactive oxygen species 5. Additionally, cryopreservation reduces both sperm metabolism and mitochondrial activity and alters sperm chromatin structure 6. All these effects result in lower motility and fertilizing capacity of frozen-thawed sperm when compared to untreated cells. Despite substantial improvements of protocols for cryopreservation of sperm and development of new extenders, it is currently accepted that 40 to 50% of sperm are incapable of proper fertilization after freezing and thawing 1. Studies indicate that certain males with nearly identical sperm parameters measured in fresh ejaculates present contrasting sperm viability after cryopreservation 7 and some bulls with high reproductive performance in natural mating have poor ...

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The occurrence of vitamin D deficiency has become an issue of serious concern in the worldwide population. As a result numerous analytical methods have been developed, for a variety of matrices, during the last few years to measure vitamin D analogs and metabolites. This review employs a comprehensive search of all vitamin D methods developed during the last 5 years for all applications, using ISI Web of Science(®), Scifinder(®), Science Direct, Scopus and PubMed. Particular emphasis is given to sample-preparation methods and the different forms of vitamin D measured across different fields of applications such as biological fluids, food and pharmaceutical preparations. This review compares and critically evaluates a wide range of approaches and methods, and hence it will enable readers to access developments across a number of applications and to select or develop the optimal analytical method for vitamin D for their particular application.