Genetics and Breeding Division, ICAR-Central Institute for Research on Goats, Makhdoom, Farah, Mathura, Uttar Pradesh, 281122, India.
Sci Rep. 2021 Mar 10;11(1):5619. doi: 10.1038/s41598-021-85094-9.
Goat milk is a source of nutrition in difficult areas and has lesser allerginicity than cow milk. It is leading in the area for nutraceutical formulation and drug development using goat mammary gland as a bioreactor. Post translational modifications of a protein regulate protein function, biological activity, stabilization and interactions. The protein variants of goat milk from 10 breeds were studied for the post translational modifications by combining highly sensitive 2DE and Q-Exactive LC-MS/MS. Here we observed high levels of post translational modifications in 201 peptides of 120 goat milk proteins. The phosphosites observed for CSN2, CSN1S1, CSN1S2, CSN3 were 11P, 13P, 17P and 6P, respectively in 105 casein phosphopeptides. Whey proteins BLG and LALBA showed 19 and 4 phosphosites respectively. Post translational modification was observed in 45 low abundant non-casein milk proteins mainly associated with signal transduction, immune system, developmental biology and metabolism pathways. P is reported for the first time in 47 sites. The rare conserved peptide sequence of (SSSEE) was observed in αS1 and αS2 casein. The functional roles of identified phosphopeptides included anti-microbial, DPP-IV inhibitory, anti-inflammatory and ACE inhibitory. This is first report from tropics, investigating post translational modifications in casein and non-casein goat milk proteins and studies their interactions.
羊奶是困难地区的营养来源，其过敏反应性低于牛奶。它在利用山羊乳腺作为生物反应器进行营养配方和药物开发方面处于领先地位。蛋白质的翻译后修饰调节蛋白质的功能、生物活性、稳定性和相互作用。通过结合高灵敏度的 2DE 和 Q-Exactive LC-MS/MS，研究了来自 10 个品种的羊奶中蛋白质的翻译后修饰。在这里，我们观察到在 120 种羊奶蛋白的 201 个肽中存在高水平的翻译后修饰。CSN2、CSN1S1、CSN1S2、CSN3 的磷酸化位点分别为 11P、13P、17P 和 6P，在 105 个酪蛋白磷酸肽中观察到。BLG 和 LALBA 乳清蛋白分别显示 19 和 4 个磷酸化位点。在 45 种低丰度非酪蛋白牛奶蛋白中观察到翻译后修饰，主要与信号转导、免疫系统、发育生物学和代谢途径有关。在 47 个位点首次报道了 P。在αS1 和αS2 酪蛋白中观察到（SSSEE）稀有保守肽序列。鉴定出的磷酸肽的功能作用包括抗微生物、DPP-IV 抑制、抗炎和 ACE 抑制。这是第一次在热带地区对酪蛋白和非酪蛋白羊奶蛋白的翻译后修饰进行研究，并研究它们的相互作用。
