Solution structure of termite-derived antimicrobial peptide, spinigerin, as determined in SDS micelle by NMR spectroscopy.
Spinigerin is a linear antibacterial peptide derived from a termite insect. It consists of 25 amino acids and is devoid of cysteines. Spinigerin displays good lytic activities against Gram-positive and Gram-negative bacteria, but has no hemolytic activities against human erythrocytes. In this study, we present a three-dimensional solution structure of spinigerin in SDS micelles. According to CD data spinigerin has an alpha-helical conformation in the presence of TFE, DPC micelles, and SDS micelles. The three-dimensional structure of spinigerin as determined by NMR spectroscopy contains a stable alpha-helix from Lys4 to Thr23. Spinigerin (4-21), an 18-residue fragment from Lys4 to Leu21, contains a similar content of alpha-helical structure compared to native spinigerin and was found to retain antibacterial activity, too. Therefore, this alpha-helical structure and the strong electrostatic attraction between four Lys and three Arg residues in spinigerin and the negatively charged polar head groups of the phospholipids on the membrane surface play important roles in disrupting membrane and subsequent cell death.
Lee
Kwang Hwan
KH
Department of Chemistry, Konkuk University, Seoul 143-701, South Korea.
Shin
Song Yub
SY
Hong
Jung Eun
JE
Yang
Sung-Tae
ST
Kim
Jae Il
JI
Hahm
Kyung-Soo
KS
Kim
Yangmee
Y
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides; D002942:Circular Dichroism; D006461:Hemolysis; D006801:Humans; D020049:Isoptera / Q000737:chemistry; D008081:Liposomes; D008823:Micelles; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides; D010743:Phospholipids; D011487:Protein Conformation; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013329:Structure-Activity Relationship
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D008081:Liposomes; D008823:Micelles; D010455:Peptides; D010743:Phospholipids; C428303:spinigerin; D012967:Sodium Dodecyl Sulfate