Lumbricin I, a novel proline-rich antimicrobial peptide from the earthworm: purification, cDNA cloning and molecular characterization.

Abstract

A novel antimicrobial peptide was isolated and characterized from the earthworm, Lumbricus rubellus. The antimicrobial peptide was purified to homogeneity by a heparin-affinity column and C18 reverse-phase HPLC, and named lumbricin I. Lumbricin I was a proline-rich antimicrobial peptide of 62 amino acids (15% proline in molar ratio; molecular mass, 7231 Da), whose complete sequence was determined by a combination of peptide sequence and cDNA analysis. The peptide and cDNA sequence analysis revealed that lumbricin I was produced as a precursor form consisting of 76 amino acids, with 14 residues in a presegment and 62 residues in mature lumbricin I. Lumbricin I showed antimicrobial activity in vitro against a broad spectrum of microorganisms without hemolytic activity. In addition, a 29-amino acid peptide, named lumbricin I(6-34), which was derived from residues 6-34 of lumbricin I, showed marginally stronger antimicrobial activity than lumbricin I. Northern blot analysis on total RNA revealed that expression of lumbricin I gene was not induced by bacterial infection, but was constitutively expressed. Furthermore, the expression of lumbricin I gene was specific in adult L. rubellus: Lumbricin I mRNA was detected only in adult L. rubellus, but not in eggs and young L. rubellus.

• Authors: J H Cho, C B Park, Y G Yoon, S C Kim
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1408 Issue 1 Pg. 67-76 (Oct 22 1998) ISSN: 0006-3002 [Print] Netherlands
• PMID: 9784609 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Bacterial Agents
• Anti-Infective Agents
• DNA, Complementary
• Peptides
• Proteins
• Recombinant Proteins
• lumbricin I

Topics

• Amino Acid Sequence
• Animals
• Annelida
• Anti-Bacterial Agents
• Anti-Infective Agents (chemistry, isolation & purification, pharmacology)
• Base Sequence
• Cloning, Molecular
• DNA, Complementary
• Fungi (drug effects)
• Gram-Negative Bacteria (drug effects)
• Gram-Positive Bacteria (drug effects)
• Leeches
• Microbial Sensitivity Tests
• Molecular Sequence Data
• Molecular Weight
• Oligochaeta (genetics)
• Oocytes (physiology)
• Peptides
• Polymerase Chain Reaction
• Proteins (analysis, chemistry, genetics, pharmacology)
• Recombinant Proteins (biosynthesis, chemistry, pharmacology)
• Sequence Alignment
• Sequence Homology, Amino Acid
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization