Quantitative Proteomics Analysis Insights into the Cordyceps Polysaccharides Biosynthesis.

Cordyceps polysaccharides, as bioactive macromolecules derived from Cordyceps sinensis, exhibit pharmacological activities such as immune modulation and anti-tumor properties. However, the understanding of their biosynthetic mechanisms remains limited. To elucidate the molecular changes associated with differentially expressed proteins (DEPs) during Cordyceps polysaccharide biosynthesis, a total of 1,242 DEPs enriched during this process were identified and annotated using the TMT-based quantitative proteomics. Subsequently, comparative analyses showed that Cordyceps polysaccharide biosynthesis was most active during the logarithmic growth phase, with high activity in sugar metabolism pathways, including galactose metabolism. Notably, DEPs with glycosyltransferase activity were identified and annotated, as they play a pivotal role in polysaccharide biosynthesis. Furthermore, within KEGG pathways closely associated with polysaccharide biosynthesis, several significantly up-regulated DEPs were identified, including NOS, ID-RCD, Arp2, NAD-GDH, phaA, GGT, CYP53A1, LAD, lacZ, and AAO. Notably, several key DEPs closely associated with polysaccharide biosynthesis showed fold-changes exceeding tenfold in the logarithmic phase relative to the early stage. Additionally, qPCR analysis showed that transcriptional changes were largely consistent with protein-level differences. Interestingly, the lacZ gene may play a critical role in Cordyceps polysaccharide biosynthesis through its glycosyltransferase activity. Collectively, these findings provide a scientific basis for the metabolic regulation of Cordyceps polysaccharides.