Molecular structures of two crystalline forms of the cyclic heptapeptide antibiotic ternatin, cyclo[-beta-OH-D-Leu-D-Ile-(NMe)Ala-(NMe)Leu-Leu-(NMe)Ala-D-(NMe)Ala-].
Molecular structures of two crystalline forms of the cyclic heptapeptide antibiotic ternatin, cyclo[-beta-OH-D-Leu-D-Ile-(NMe)Ala-(NMe)Leu-Leu-(NMe)Ala-D-(NMe)Ala-].
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环七肽抗生素特纳汀的两种晶型的分子结构，环[-β-OH-D-Leu-D-Ile-(NMe)Ala-(NMe)Leu-Leu-(NMe)Ala-D-(NMe)
DOI：
10.1111/j.1399-3011.1993.tb00362.x
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Ivanov,VT
中科院分区：
文献类型：
--
作者：
Miller,R;Galitsky,NM;Duax,WL;Langs,DA;Pletnev,VZ;Ivanov,VT
本文报道了两种溶剂化形式的特立亭环[-β-OH-d-Leu-d-Ile-（NMe）Ala-（NMe）Leu-Leu-（NMe）Ala-d-（NMe）Ala-]的晶体结构。第一个晶体在不对称单元中含有两个肽分子和一个二氧六环分子：P212121，a= 11.563（1），B= 21.863（2），c= 36.330（4）π。第二个晶体在不对称单元中含有两个肽分子和一个水分子：P212121，a= 14.067（2），B= 16.695（1），c= 36.824（6）π。这里观察到的四个分子中的每一个的主链都采用相同的H键大环构象。所有的氨基酸侧链，除了d-Ile 2，在四种构象中的每一种都有相似的方向。所述七肽大环化合物的特征在于：（i）（NMe）Ala 3和（NMe）Leu 4之间的酸肽，（ii）II型β-弯曲，涉及残基Leu 5-（NMe）Ala 6-d-（NMe）Ala 7-β-OH-d-Leu 2，通过Leu 5和β-OH-d-Leu 1残基之间的两个H-键N1′05和N5′01稳定，（iii）在四个分子中的每一个中观察到的第三个分子内H-键，β-OH-d-Leu 1的羟基和d-Ile 2的羰基氧之间。
The crystal structures of two solvated forms of ternatin, cyclo[‐β‐OH‐d‐Leu‐d‐Ile‐(NMe)Ala‐(NMe)Leu‐Leu‐(NMe)Ala‐d‐(NMe)Ala‐] are reported. The first crystallizes with two molecules of peptide and one of dioxane in the asymmetric unit:P212121,a= 11.563(1),b= 21.863(2),c= 36.330(4) Å. The second crystallizes with two molecules of peptide and one of water in the asymmetric unit:P212121,a= 14.067(2),b= 16.695(1),c= 36.824(6) Å.N‐Methylation of four of the seven residues of ternatin appears to reduce the number of low‐energy conformations the molecule can assume. The same H‐bonded macrocyclic ring conformation is adopted by the backbone of each of the four molecules observed here. All the amino‐acid side chains, with the exception ofd‐Ile2, have similar orientations in each of the four conformers. The heptapeptide macrocycle is characterized by: (i) acispeptide between (NMe)Ala3and (NMe)Leu4, (ii) a type II β‐bend, involving residues Leu5‐(NMe)Ala6‐d‐(NMe)Ala7‐β‐OH‐d‐Leu2, stabilized by two H‐bonds, N1′05 and N5′01, between Leu5and β‐OH‐d‐Leu1residues, (iii) a third intramolecular H‐bond, observed in each of the four molecules, between the hydroxyl group of β‐OH‐d‐Leu1and the carbonyl oxygen ofd‐Ile2.