- 生物活性
Indolicidin是从牛嗜中性粒细胞的细胞质颗粒中纯化的有效的抗微生物肽。
- 体外研究
Indolicidin is comprised of 13 amino acids, 5 of which are tryptophan residues, and the carboxylterminal arginine is carboxamidated. Indolicidin has the highest tryptophan content of any known protein. The multiple tryptophan residues may play an important role in the function of this unique antibiotic peptide. Indolicidin is a tridecapeptide amide which possesses
in vitro
bactericidal activities comparable with the most active of the defensin or bactenecin peptides. Indolicidin binds purified surface lipopolysaccharide with high affinity and permeabilized the outer membrane of
Escherichia coli
to the small hydrophobic molecule 1-N-phenylnapthylamine (Mr 200), results consistent with indolicidin crossing the outer membrane via the self-promoted uptake pathway. The methyl esterification of indolicidin's carboxyl terminus increases its activity for Gram-negative and Gram-positive bacteria. In Gram-negative bacteria this is associated with an increased binding to lipopolysaccharide and increased permeabilization of the outer membrane. The cytoplasmic membrane is the site of action of indolicidin as assayed in
Escherichia coli
by the unmasking of cytoplasmic beta-galactosidase due to membrane permeabilization.
- 多肽
抗菌肽Indolicidin是从牛中性粒细胞胞质颗粒中分离得到的一种抗菌肽。其结构为ＩＬＰＷＫＷＰＷＷＰＷＲＲ￣ＮＨ２，仅包含6种共13个氨基酸，是目前为止已知的最小的天然线性抗菌肽之一。该多肽的羧基端被酰胺化，共包含 ３９％ 的色氨酸残基和 ２３％的脯氨酸残基。这是 Ｃａｔｈｅｌｉｃｉｄｉｎｓ 家族甚至是目前已知蛋白质中色氨酸含量最高的多肽之一。Indolicidin抗菌谱广，对多种需氧革兰氏阴性菌、革兰氏阳性菌和真菌都有很强的抗菌活性。
- 参考质量标准
外观:白色粉末
纯度(HPLC) ≥98.0%
醋酸根含量≤12.0%
水分含量≤8.0%
肽含量≥80.0%
内毒素≤50EU/mg
氨基酸组成分析≤±10%
