2RNG

Solution structure of big defensin

2RNG の概要

• エントリーDOI: 10.2210/pdb2rng/pdb
• NMR情報: BMRB: 11022
• 分子名称: Big defensin (1 entity in total)
• 機能のキーワード: alpha-helices & beta-sheets, three disulfide bridges, antibiotic, antimicrobial, fungicide, secreted, antimicrobial protein
• 由来する生物種: Tachypleus tridentatus (Japanese horseshoe crab)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 8646.87

構造登録者

Kouno, T.,Fujitani, N.,Osaki, T.,Kawabata, S.,Nishimura, S.,Mizuguchi, M.,Aizawa, T.,Demura, M.,Nitta, K.,Kawano, K. (登録日: 2007-12-27, 公開日: 2008-10-14, 最終更新日: 2024-10-30)

主引用文献

Kouno, T.,Fujitani, N.,Mizuguchi, M.,Osaki, T.,Nishimura, S.,Kawabata, S.,Aizawa, T.,Demura, M.,Nitta, K.,Kawano, K.
A novel beta-defensin structure: a potential strategy of big defensin for overcoming resistance by Gram-positive bacteria
Biochemistry, 47:10611-10619, 2008

PubMed Abstract: Big defensin is a 79-residue peptide derived from hemocytes of the Japanese horseshoe crab. It has antimicrobial activities against Gram-positive and -negative bacteria. The amino acid sequence of big defensin can be divided into an N-terminal hydrophobic half and a C-terminal cationic half. Interestingly, the trypsin cleaves big defensin into two fragments, the N-terminal and C-terminal fragments, which are responsible for antimicrobial activity against Gram-positive and -negative bacteria, respectively. To explore the antimicrobial mechanism of big defensin, we determined the solution structure of mature big defensin and performed a titration experiment with DPC micelles. Big defensin has a novel defensin structure; the C-terminal domain adopts a beta-defensin structure, and the N-terminal domain forms a unique globular conformation. It is noteworthy that the hydrophobic N-terminal domain undergoes a conformational change in micelle solution, while the C-terminal domain remains unchanged. Here, we propose that the N-terminal domain achieves its antimicrobial activity in a novel fashion and explain that big defensin has developed a strategy different from those of other beta-defensins to suppress the growth of Gram-positive bacteria.

PubMed: 18785751
DOI: 10.1021/bi800957n

実験手法

SOLUTION NMR