Screening and identification of the mimic peptide of Mycobacterium tuberculosis antigen / 中华微生物学和免疫学杂志

ObjectiveTo immunoscreen the mimic peptides of Mycobacterium tuberculosis antigen from phage displayed 12-mer peptide library.MethodsSpecific IgG was purified from sera of patients with TB and used as the target to immunoscreen a phage random peptide library of 12 amino acids.Positive clones which were obtained after three rounds of biopanning were detected by ELISA and sequenced.The diagnostic value of the high frequent positive clones were observed by ELISA.Results After 3 rounds of immunoscreening,the eluted phages were enriched effectively.Six kinds of animo acid sequence were obtained from twelve positive phage clones.Sensitivity of the two high frequent positive clones were 71.4％ (A2)and 55.4％ (A7) respectively.ConclusionThe antigen-mimic peptide was successfully screened from 12 random phage peptide library and the peptides can be recognized by tuberculosis patients' polyclonal antibodies.

Selection of Cd~(2+) Binding-peptides and Their Affinities for Heavy Metal Ions / 微生物学通报

Selection and affinities of Cd binding peptides were assayed by phage random dodecapeptide library and affinity chromatography. Two Cd binding peptides were obtained, it was found that the affinities of Cu~ 2+ ,Co~ 2+ ,Zn~ 2+ ,Ni~ 2+ for Cd binding peptides were higher than that of Cd~ 2+ and Cr~ 2+ after detection of the amplified Cd binding peptides displayed phages to different heavy metal-charged resins; the detoxification of E.coli to Ni~ 2+ and Cd~ 2+ was enhanced when infected by Cd binding peptide displayed phages as compared with those of the control. The interaction of Cd binding peptide displayed phages with heavy metals charged resins was also observed under microscope. The work would be of great value and consequences for the study of interaction between heavy metals and proteins(peptides), as well as thedetoxification and bioremediation of heavy metals.