Protease Inhibitors Protect Bovine Colostrum or Chicken Egg Growth Factors from Pancreatic Enzyme Digestion in AGS Cells or Colitic Rats

Comparative analysis of whey proteins in yak milk from different breeds in China using a data-independent acquisition proteomics method

Yak milk is rich in essential milk proteins of nutritional and therapeutic value. In this study, whey proteins of milk from 3 yak breeds (Gannan, GN; Huanhu, HH; Maiwa, MW) in China were comprehensively identified and compared using a data-independent acquisition quantitative proteomics approach. A total of 632 proteins were identified in yak milk whey samples, in which immune-related proteins were abundant. Compared with other milks, more proteins were involved in oxidation-reduction process and with ATP binding. In addition, we identified 96, 155, and 164 differentially expressed proteins (DEP) for GN versus HH, GN versus MW, and HH versus MW, respectively. "Phagosome" and "complement and coagulation cascades" were the most significant pathways for DEP of GN versus HH and GN or HH versus MW yak milk based on the Kyoto Encyclopedia of Genes and Genomes pathway analysis. Protein-protein interaction network analysis showed that DEP for the 3 comparisons had significant biological interactions but were associated with different functions. The results provide useful information on yak milk from different breeds in China, and elucidate the biological functions of yak milk proteins.

Minor structural changes, major functional impacts: posttranslational modifications and drug targets

Posttranslational modifications (PTMs) are essential mechanisms that provide chemical diversity to proteins. The additional functional and structural elements can be introduced to exceed the primary amino acid composition. PTMs impact key biological and physiological processes including cell signaling, metabolism, protein degradation and influences interactions with other macromolecules. However, characterization of the structural and functional signatures of modified proteins has been historically limited. Since defects in PTMs are linked to numerous disorders and diseases, PTMs and their modifying enzymes are considered as potential drug targets. This has fueled new initiatives to determine how PTMs affect protein structure and function. In this review, I summarize some of the major, well-studied protein PTMs and related drug targets. Since PTMs are widely used for therapeutic targets or disease markers, highlighting structural changes after PTM provides new frontiers in understanding the detailed mechanism and related drug developments.