[Construction and analysis of a deep-coverage proteomic map of Mycobacterium avium based on high-resolution mass...

Mycobacterium avium is an important zoonotic nontuberculous mycobacteria (NTM), and its continuously rising infection rate has posed a severe public health challenge. However, due to the incomplete annotation of protein-coding sequences in the reference genome and the absence of proteomic data for the type strain, the expression profiles of the proteins encoded by this bacterium remain poorly characterized. To address the gap between genome prediction annotation and protein expression, it is crucial to acquire systematic and reliable experimental evidence of proteins at the type strain level. This study conducted an in-depth mass spectrometry analysis of whole-cell and the secreted proteins from the type strain M. avium DSM 44156^T. We employed a highly active acetylated trypsin developed by our laboratory for digestion, combined with high-pH reversed-phase fractionation. A total of 3 655 non-redundant proteins, 32 917 peptides, and 91 744 spectra were identified, covering 82.90% of the 4 409 coding genes in the NCBI reference protein database. The whole-cell and secretory proteomes exhibited pronounced complementarity, with a total of 2 445 proteins in common, while 1 114 and 96 unique proteins were specifically detected in the whole-cell and secreted fractions, respectively. This study has constructed a comprehensive and high-precision standardized proteomic map of M. avium, which not only supplements the protein expression data for this species but also provides key data support for further elucidating its pathogenic mechanism, screening novel diagnostic markers and therapeutic targets, and formulating prevention and control strategies for NTM-related zoonoses.