V Pavone, B Di Blasio, A Lombardi, O Maglio, C Isernia, C Pedone, E Benedetti, E Altmann, M Mutter
{"title":"非编码C, α -二取代氨基酸。含(S)- α -甲基丝氨酸二肽的x射线衍射分析。","authors":"V Pavone, B Di Blasio, A Lombardi, O Maglio, C Isernia, C Pedone, E Benedetti, E Altmann, M Mutter","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>The crystal and molecular structure of the fully protected dipeptide Boc-Val-(S)-alpha-MeSer-OMe has been determined by X-ray diffraction techniques. Crystals grown from ethyl acetate/n-pentane mixtures are tetragonal, space group I4(1), with cell parameters at 295 K of a = 15.307(2), c = 18.937(10)A, V = 4437.1A3, M.W. = 332.40, Z = 8, Dm = 0.99 g/cm3 and Dx = 0.995 g/cm3. The structure was solved by application of direct methods and refined to an R value of 0.028 for 1773 reflections with I > or = 3 sigma (I) collected on a CAD-4 diffractometer. Both chiral centers have the (S) configuration. The dipeptide assumes in the solid state an S shape. The urethane moiety is in the cis conformation, while the amide bond is in the common trans conformation. The conformational angles phi 1, psi 1 of the Val and phi 2, and psi 2 of the (S)-alpha MeSer fall in the F region of the phi-psi map. The isopropyl side chain of the Val residue has the (t, g-) conformation, while the Ser side chain has a g+ conformation. The hydrogen bond donor groups are all involved in intermolecular H-bond interactions. Along the quaternary axis the dipeptide molecules are linked to each other with the formation of infinite rows.</p>","PeriodicalId":14204,"journal":{"name":"International journal of peptide and protein research","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Non coded C alpha, alpha-disubstituted amino acids. X-ray diffraction analysis of a dipeptide containing (S)-alpha-methylserine.\",\"authors\":\"V Pavone, B Di Blasio, A Lombardi, O Maglio, C Isernia, C Pedone, E Benedetti, E Altmann, M Mutter\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The crystal and molecular structure of the fully protected dipeptide Boc-Val-(S)-alpha-MeSer-OMe has been determined by X-ray diffraction techniques. Crystals grown from ethyl acetate/n-pentane mixtures are tetragonal, space group I4(1), with cell parameters at 295 K of a = 15.307(2), c = 18.937(10)A, V = 4437.1A3, M.W. = 332.40, Z = 8, Dm = 0.99 g/cm3 and Dx = 0.995 g/cm3. The structure was solved by application of direct methods and refined to an R value of 0.028 for 1773 reflections with I > or = 3 sigma (I) collected on a CAD-4 diffractometer. Both chiral centers have the (S) configuration. The dipeptide assumes in the solid state an S shape. The urethane moiety is in the cis conformation, while the amide bond is in the common trans conformation. The conformational angles phi 1, psi 1 of the Val and phi 2, and psi 2 of the (S)-alpha MeSer fall in the F region of the phi-psi map. The isopropyl side chain of the Val residue has the (t, g-) conformation, while the Ser side chain has a g+ conformation. The hydrogen bond donor groups are all involved in intermolecular H-bond interactions. Along the quaternary axis the dipeptide molecules are linked to each other with the formation of infinite rows.</p>\",\"PeriodicalId\":14204,\"journal\":{\"name\":\"International journal of peptide and protein research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1993-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International journal of peptide and protein research\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International journal of peptide and protein research","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
用x射线衍射技术测定了完全保护二肽Boc-Val-(S)- α - meser - ome的晶体和分子结构。从乙酸乙酯/正戊烷混合物中生长出的晶体为四边形,空间群为I4(1),在295 K时,细胞参数为a = 15.307(2), c = 18.937(10) a, V = 4437.1A3, m.w = 332.40, Z = 8, Dm = 0.99 g/cm3, Dx = 0.995 g/cm3。采用直接法对CAD-4衍射仪采集的1773个I >或= 3 sigma (I)的反射信号进行了结构求解,并将其R值细化为0.028。两个手性中心都是S构型。二肽呈固态S形。聚氨酯部分呈顺式构象,而酰胺键呈常见的反式构象。构象角1,Val的1和2的1,S - MeSer的2落在-映射的F区。Val残基的异丙基侧链为(t, g-)构象,而Ser侧链为g+构象。氢键给基都参与了分子间氢键的相互作用。沿着四轴,二肽分子相互连接,形成无限行。
Non coded C alpha, alpha-disubstituted amino acids. X-ray diffraction analysis of a dipeptide containing (S)-alpha-methylserine.
The crystal and molecular structure of the fully protected dipeptide Boc-Val-(S)-alpha-MeSer-OMe has been determined by X-ray diffraction techniques. Crystals grown from ethyl acetate/n-pentane mixtures are tetragonal, space group I4(1), with cell parameters at 295 K of a = 15.307(2), c = 18.937(10)A, V = 4437.1A3, M.W. = 332.40, Z = 8, Dm = 0.99 g/cm3 and Dx = 0.995 g/cm3. The structure was solved by application of direct methods and refined to an R value of 0.028 for 1773 reflections with I > or = 3 sigma (I) collected on a CAD-4 diffractometer. Both chiral centers have the (S) configuration. The dipeptide assumes in the solid state an S shape. The urethane moiety is in the cis conformation, while the amide bond is in the common trans conformation. The conformational angles phi 1, psi 1 of the Val and phi 2, and psi 2 of the (S)-alpha MeSer fall in the F region of the phi-psi map. The isopropyl side chain of the Val residue has the (t, g-) conformation, while the Ser side chain has a g+ conformation. The hydrogen bond donor groups are all involved in intermolecular H-bond interactions. Along the quaternary axis the dipeptide molecules are linked to each other with the formation of infinite rows.