Serinocyclins A and B, cyclic heptapeptides from Metarhizium anisopliae
Serinocyclins A and B, cyclic heptapeptides from Metarhizium anisopliae
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DOI：
10.1021/np070407i
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发表时间：
2007-12-01
影响因子：
5.1
通讯作者：
Gibson, Donna M.
中科院分区：
文献类型：
--
作者：
Krasnoff, Stuart B.;Keresztes, Ivan;Gibson, Donna M.
从昆虫病原真菌金龟子绿僵菌（Metarhiziumanisopliae）分生孢子中分离到两个新的环七肽，即丝素环素A（serinocyclins A，1）和B（serinocyclins B，2）。通过质谱、NMR和X射线衍射技术的组合来阐明结构。丝氨酸环素A（1）含有三个丝氨酸单位，一个羟脯氨酸（Hyp），一个β-丙氨酸（β-Ala），和两个不常见的非蛋白质氨基酸，1-氨基环丙烷-1-羧酸（Acc）和γ-羟赖氨酸（HyLys）。通过NMR确定的I的肽序列为环-（Acc-Hyp-Ser 1-HyLys-beta-Ala-Ser 2-Ser 3）。丝氨酸环素B（2）用Lys取代了1中的HyLys单位。手性氨基酸分析表明两种化合物中均存在一个（2S，4 R）-Hyp、两个L-Ser和一个D-Ser残基。在2的水解产物中发现的赖氨酸被确定为D-构型。1的晶体结构确定了D-Ser（Ser 2）的位置和HyLys单元（2 R，4S）的绝对构型。甲基的缺失在真菌肽中是不寻常的，并且沿着带电赖氨酰侧链和多个羟基，有助于化合物的极性性质。Serinocyclin A在蚊子幼虫中产生亚致死运动缺陷，EC 50为59 ppm。
Two new cyclic heptapeptides, serinocyclins A (1) and B (2), were isolated from conidia of the entomopathogenic fungus Metarhizium anisopliae. Structures were elucidated by a combination of mass spectrometric, NMR, and X-ray diffraction techniques. Serinocyclin A (1) contains three serine units, a hydroxyproline (Hyp), a beta-alanine (beta-Ala), and two uncommon nonproteinogenic amino acids, 1-aminocyclopropane-1-carboxylic acid (Acc) and gamma-hydroxylysine (HyLys). The peptide sequence established for I by NMR is cyclo-(Acc-Hyp-Ser1-HyLys-beta-Ala-Ser2-Ser3). Serinocyclin B (2) has Lys in place of the HyLys unit found in 1. Chiral amino acid analysis indicated the presence in both compounds of one (2S,4R)-Hyp, two L-Ser, and one D-Ser residue. A Lys found in the hydrolyzate of 2 was established as D-configured. A crystal structure of 1 established the position of the D-Ser (Ser2) and the absolute configuration of the HyLys unit (2R,4S). The absence of methyl groups is unusual among fungal peptides and, along with the charged lysyl side chain and multiple hydroxyl groups, contributes to the polar nature of the compounds. Serinocyclin A produced a sublethal locomotory defect in mosquito larvae at an EC50 of 59 ppm.