STUDY OF SECONDARY STRUCTURE OF ILAMYCIN-B1 BY 300 MHZ PROTON MAGNETIC RESONANCE
STUDY OF SECONDARY STRUCTURE OF ILAMYCIN-B1 BY 300 MHZ PROTON MAGNETIC RESONANCE
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DOI：
10.1016/0014-5793(71)80584-7
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发表时间：
1971-01-01
期刊：
影响因子：
3.5
通讯作者：
OHNISHI, M
中科院分区：
文献类型：
--
作者：
CARY, LW;TAKITA, T;OHNISHI, M
最近的PMR和X射线研究表明，几种环状多肽抗生素的共同构象特征是与反平行折叠片结构相关的P-转角[1171]。在PMR参数中，p-转角的特征在于酰胺质子共振，其由于邻位肽部分的磁各向异性而转移到高场，并且由于分子内氢键而具有低温度系数。还观察到了具有小的c~-CHNH耦合常数的信号，反映了角部处的邻二面角。迄今为止研究的环肽具有偶数个残基，包括甘氨酸或D-氨基酸，其在能量上有利于形成转角的角[16-201]。这项研究的目的是看看如果一个环肽与一个，奇数
Recent PMR and X-ray studies have shown that a common conformational feature of several cyclic polypeptide antibiotics is the P-turn associated with antiparallel pleated sheet structures [ll 71. In PMR parameters, the p-turn is characterized by an amide proton resonance that is shifted to high field because of the magnetic anisotropy of the vicinal peptide moiety and has a low temperature coefficient due to intramolecular hydrogen bonding. Signals with a small c~-CHNH coupling constant reflecting the vicinal dihedral angle at the corner are also observed. The cyclic peptides studied so far have an even number of residues, including a glycine or a D-amino acid which is energetically favored to form the corner of a &turn [16-201. The purpose of this study is to see if a cyclic peptide with an, odd