title: The antimicrobial activity of CCL28 is dependent on C-terminal positively-charged amino acids.
abstract: Several chemokines have been shown to act as antimicrobial proteins, suggesting a direct contribution to innate immune protection. Based on the study of defensins and other antimicrobial peptides, it has been proposed that cationic amino acids in these proteins play a key role in their antimicrobial activity. The primary structure requirements necessary for the antimicrobial activity of chemokines, however, have not yet been elucidated. Using mouse CCL28, we have identified a C-terminal region of highly-charged amino acids (RKDRK) that is essential to the antimicrobial activity of the murine chemokine. Additionally, other positively-charged amino acids in the C-terminus of the protein contribute to the observed antimicrobial effect. Charge reversal and deletion mutations support our hypothesis that C-terminal positively-charged amino acids are essential for the antimicrobial activity of CCL28. Results also demonstrate that although the C-terminal region of the chemokine is essential, it is not sufficient for full antimicrobial activity of CCL28.
authors.affiliation: Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Eric
authors.initials: E
authors.lastname: Wilson
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry / Q000276:immunology*; D000818:Animals; D019742:Chemokines, CC / Q000737:chemistry / Q000276:immunology*; D017124:Conserved Sequence; D006801:Humans; D051379:Mice; D050296:Microbial Viability; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D000596:Amino Acids; C511142:Ccl28 protein, mouse; D019742:Chemokines, CC