Peptidoglycan recognition proteins are a new class of human bactericidal proteins

Xiaofeng Lu, Minhui Wang, Jin Qi, Haitao Wang, Xinna Li, Dipika Gupta, Roman Dziarski

Research output: Contribution to journalArticlepeer-review

163 Scopus citations


Skin and mucous membranes come in contact with external environment and protect tissues from infections by producing antimicrobial peptides. We report that human peptidoglycan recognition proteins 3 and 4 (PGLYRP3 and PGLYRP4) are secreted as 89-115-kDa disulfide-linked homo- and heterodimers and are bactericidal against several pathogenic and nonpathogenic transient, but not normal flora, Gram-positive bacteria. PGLYRP3 and PGLYRP4 are also bacteriostatic toward all other tested bacteria, which include Gram-negative bacteria and normal flora Gram-positive bacteria. PGLYRP3 and PGLYRP4 are also active in vivo and protect mice against experimental lung infection. In contrast to antimicrobial peptides, PGLYRPs kill bacteria by interacting with their cell wall peptidoglycan, rather than permeabilizing their membranes. PGLYRP3 and PGLYRP4 are expressed in the skin, eyes, salivary glands, throat, tongue, esophagus, stomach, and intestine. Thus, we have identified the function of mammalian PGLYRP3 and PGLYRP4, and show that they are a new class of bactericidal and bacteriostatic proteins that have different structures, mechanism of actions, and expression patterns than antimicrobial peptides.

Original languageEnglish (US)
Pages (from-to)5895-5907
Number of pages13
JournalJournal of Biological Chemistry
Issue number9
StatePublished - Mar 3 2006

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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