Update publication information. The secreted proteome and bacteria proteome of yersinia pestis at 26 ℃ mimic flea. Y. pestis strain 201 cultures grown under Fv (26°C, TMH with 2.5M calcium) condition. The bacteria pellets and supernant were used as the experimental and control groups, respectively. After 8 h of incubation, the cultures supernatants were collected by centfugation and concentrated using centrifugal filters. The concentrations of proteins were determined using a Pierce BCA Protein Assay Kit. Tandem mass tag labeling was used to obtain accurate quantitative information to minimize variability between samples. For quantitative analysis, at least two unique peptides were used for the identification and quantification of proteins.