Proteomic insights into goat milk serum proteins at varying altitudes in China.

Using Astral DIA quantitative proteomics, this study characterized serum protein profiles and potential functions of goat milk from different altitude regions. A total of 1446 proteins were identified, with 1268, 1256, and 1346 proteins detected in high-altitude, mid-altitude, and low-altitude samples, respectively. The high-altitude sample contained 34 unique proteins and showed higher abundances of α-lactalbumin, serum albumin, and polymeric immunoglobulin receptor, whereas the low-altitude sample contained 87 unique proteins and higher abundances of several immune-related proteins, including osteopontin, lactoferrin, immunoglobulin, lysozyme, xanthine oxidase, lactoperoxidase, and GLYCAM1. Differentially expressed analysis identified 453, 452, and 113 differential proteins in high-altitude vs. low-altitude, mid-altitude vs. low-altitude, and high-altitude vs. mid-altitude comparisons, respectively. KEGG analysis showed that carbohydrate metabolism was enriched in comparisons involving the low-altitude sample, whereas amino acid metabolism was enriched between high-altitude and mid-altitude samples. Notably, HIF-1 signaling pathway was enriched in the high-altitude sample, suggesting hypoxia-associated proteomic adaptation.