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Renganayaki S, Govindasamy L, Subramanian E. Crystal and Molecular Structure of 4-methoxy-carbonyl methyl-2,9-bis(phenylsulfonyl)-1,2,3,4-tetrahydro β-carboline : benzene solvate. CRYSTAL RESEARCH AND TECHNOLOGY 1998. [DOI: 10.1002/(sici)1521-4079(1998)33:6<963::aid-crat963>3.0.co;2-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Subramanian E, Govindasamy L, Ravichandran K. trans-Methyl 2,9-Bis(phenylsulfonyl)-1,2,3,4-tetrahydro-4-β-carbolinylideneacetate. Acta Crystallogr C 1997. [DOI: 10.1107/s010827019700228x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Mitra SN, Govindasamy L, Subramanian E. L-Leucyl-L-alanine Dimethyl Sulfoxide Solvate. Acta Crystallogr C 1996. [DOI: 10.1107/s0108270196007743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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Sivaraman J, Subramanian K, Velmurugan D, Subramanian E, Seetharaman J, Shanmugasundaram P. X-ray structure of 5-[2-chlorophenyl]-10-[4-methylphenyl] 1,2,5,8,9,10 hexahydro 4,6[3H,6H] acridinedione and its interaction with calf thymus DNA by spectroscopic methods. J Mol Struct 1996. [DOI: 10.1016/s0022-2860(96)09355-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sivaraman J, Subramanian K, Velmurugan D, Subramanian E, Shanmugasundram PS. 3,3,6,6-Tetramethyl-10-(4-methylphenyl)-3,4,6,7,9,10-hexahydro-1,8(2H,5H)-acridinedione. Acta Crystallogr C 1996. [DOI: 10.1107/s0108270195010171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Padha N, Subramanian E, Dass AK, Mazumdar SK, Goswami KN. Crystal structure of a furo-[3,2-g]-[1]-benzopyran-7-one derivative. CRYSTAL RESEARCH AND TECHNOLOGY 1995. [DOI: 10.1002/crat.2170300213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Sivaraman J, Subramanian K, Velmurugan D, Subramanian E, Ramakrishnan VT. 9-Methyl-10-(4-methylphenyl)-3,4,6,7,9,10-hexahydro-1,8(2H,5H)-acridinedione. Acta Crystallogr C 1994. [DOI: 10.1107/s0108270194002805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Shanmuga Sundara Raj S, Velmurugan D, Subramanian E, Kandaswamy M. 4-tert-Butyl-2,6-bis[(4-methyl-1-piperazinyl)methyl]phenol. Acta Crystallogr C 1994. [DOI: 10.1107/s010827019400034x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Shanmuga Sundara Raj S, Velmurugan D, Subramanian E, Kandaswamy M. 4-Chloro-2,6-bis(morpholinomethyl)phenol. Acta Crystallogr C 1994. [DOI: 10.1107/s0108270194000351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Mitra SN, Subramanian E. Observation of a sterically unfavorable side-chain conformation in a leucyl residue: crystal and molecular structure of L-leucyl-L-leucine.DMSO solvate. Biopolymers 1994; 34:1139-43. [PMID: 7948727 DOI: 10.1002/bip.360340903] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The crystal structure of a dipeptide L-leucyl-L-leucine (C12H24N2O3) has been determined. The crystals are monoclinic, space group P2(1), with a = 5.434(4) A, b = 15.712(7) A, c = 11.275(2) A, beta = 100.41(1) degrees, and Z = 2. The crystals contain one molecule of dimethyl sulfoxide (DMSO) as solvent of crystallization for each dipeptide molecule. The structure has been solved by direct methods and refined to a final R index of 0.059 for 920 reflections (sin theta/lambda < or = 0.60 A-1) with I > or = 2 sigma (I). The trans peptide unit shows substantial degree of non-planarity (delta omega = 14 degrees). The peptide backbone adopts an extended conformation with torsion angles of psi 1 = 138(1) degrees, omega 1 = 166(1) degrees, phi 2 = -149.3(7) degrees, psi 21 = 164.2(7) degrees, and psi 22 = -15(1) degrees. For the first leucyl residue, the side-chain conformation is specified by the torsion angles 1 chi 1 = 176.7(7) degrees, 1 chi 21 = 62(1) degrees, 1 chi 22 = -177.4(8) degrees; the second leucyl residue adopts a sterically unfavorable conformation with 2 chi 1 = 61(1) degrees, 2 chi 21 = 97(1) degrees, and 2 chi 22 = -151(1) degrees. The packing involves head-to-tail interaction of peptide molecules and segregation of polar and nonpolar regions. The DMSO molecule is strongly hydrogen bonded to the terminal NH3+ group.
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Velmurugan D, Govindasamy L, Subramanian E, Rajendran TM, Kandaswamy M. 2,6-Bis[(4-methyl-1-piperazinyl)methyl]-4-nitrophenol. Acta Crystallogr C 1994. [DOI: 10.1107/s0108270193010273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Sivaraman J, Subramanian K, Velmurugan D, Subramanian E, Sadanandan EV. [2-(3,4-Methylenedioxyphenyl)-1-(phenylsulfonyl)vinyl]-3-(phenylthio)indole. Acta Crystallogr C 1994. [DOI: 10.1107/s0108270193008285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Sivaraman J, Subramanian K, Velmurugan D, Subramanian E, Sadanandan EV. 2-[1-Phenylsulfonyl-2-(3,4,5-trimethoxyphenyl)vinyl]-3-(phenylthio)indole. Acta Crystallogr C 1994. [DOI: 10.1107/s0108270193009977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Sivaraman J, Subramanian K, Velmurugan D, Subramanian E, Sadanandan EV. 2-[2-(4-Methoxyphenyl)-1-(phenylsulfonyl)vinyl]-3-(phenylthio)indole. Acta Crystallogr C 1994. [DOI: 10.1107/s0108270193001817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Prasad S, Mitra S, Subramanian E, Velmurugan D, Rao RB, Balaram P. Coexistence of folded and extended conformations of a tripeptide containing alpha, alpha -di-n-propylglycine in crystals. Biochem Biophys Res Commun 1994; 198:424-30. [PMID: 8297351 DOI: 10.1006/bbrc.1994.1062] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The crystal structure of the tripeptide Boc-Leu-Dpg-Val-OMe (Dpg, alpha, alpha -di-n-propylglycine) reveals the coexistence of two distinct backbone conformations. In molecule A the Dpg residue adopts a fully extended conformation (phi = 76.0 degrees, psi = 180.0 degrees) while in molecule B a left handed helical conformation (phi = 62.8 degrees, psi = 39.6 degrees) is observed. Molecule B adopts a folded structure corresponding to a highly distorted Type II beta-turn conformation, which lacks an intramolecular 4 -> 1 hydrogen bond. In contrast, molecule A has an open, extended conformation. The results demonstrate that both fully extended and helical conformations are energetically accessible to the Dpg residue.
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Subramanian E, Rajan SS, Jayashree V. Peptide models for understanding packing interactions in the interior of globular proteins: crystal structure of leucyl-leucyl-leucine HCl. Acta Crystallogr A 1993. [DOI: 10.1107/s0108767378096348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Sivaraman J, Subramanian K, Velmurugan D, Subramanian E, Ramakrishnan VT. Crystal and molecular structures of some acridine diones. Acta Crystallogr A 1993. [DOI: 10.1107/s0108767378094623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Sundara Raj SS, Velmurugan D, Subramanian E. Crystal structure of 2,6-bis-( N-methylene morpholino)-4-chlorophenyl. Acta Crystallogr A 1993. [DOI: 10.1107/s0108767378094635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Sivaraman J, Subramanian K, Velmurugan D, Subramanian E, Balakrishna K. Structure of vicogenin. Acta Crystallogr C 1993. [DOI: 10.1107/s0108270192013556] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Subramanian E, Sahayamary JJ. Structure and conformation of linear peptides. XIV. Structure of tert-butyloxycarbonyl-L-alanylglycine monohydrate. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1993; 41:319-22. [PMID: 8496012 DOI: 10.1111/j.1399-3011.1993.tb00445.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The crystal structure of a dipeptide tert-butyloxycarbonyl-L-alanylglycine monohydrate (C10H18N2O5.H2O), molecular weight 264, has been determined. The crystals are monoclinic, space group P2(1), with a = 10.767(1), b = 6.317(1), c = 10.981(2)A, beta = 109.15(2) degrees, and Z = 2, Dc = 1.24 g cm-3. The structure was solved by direct methods and refined to a final R-index of 0.045 for 856 reflections (sin theta/lambda < 0.55 A-1) with I > 2 sigma. The N-terminus of the molecule blocked with the t-Boc group is uncharged and the C-terminus exists in an unionized state. The peptide unit is trans and shows slight deviations from planarity. (delta omega = 3.1 degrees). The peptide backbone is folded, with torsion angles of phi 1 = -76.0(5), psi 1 = 164.3(4), omega 1 = 176.9(5), phi 2 = 116.1(5), psi 21 = -2.8(7) and psi 22 = 177.8(4) degrees. The conformation about the urethane bond (C5-N1) is trans. The urethane group is essential planar. The conformation of the boc group is trans-trans.
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Ananthanarayanan VS, Boulay G, Mary JS, Subramanian E, Michel AG. Crystal structure of tert.-butyloxycarbonyl-L-prolyl-D-alanyl-D-alanyl-N-methylamide. Dimeric beta-sheet formation. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1992; 39:458-63. [PMID: 1428534 DOI: 10.1111/j.1399-3011.1992.tb01450.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The crystal structure of the tripeptide t-Boc-L-Pro-D-Ala-D-Ala-NHCH3, monohydrate, (C17H30N4O5.H2O, molecular weight = 404.44) has been determined by single crystal X-ray diffraction. The crystals are monoclinic, space group P2(1), a = 9.2585(4), b = 9.3541(5), c = 12.4529(4)A, beta = 96.449(3) degrees, Z = 2. The peptide units are in the trans and the tBoc-Pro bond in the cis orientation. The first and third peptide units show significant deviations from planarity (delta omega = 5.2 degrees and delta omega = 3.7 degrees, respectively). The backbone torsion angles are: phi 1 = -60 degrees, psi 1 = 143.3 degrees, omega 1 = -174.8 degrees, phi 2 = 148.4 degrees, psi 2 = -143.1 degrees, omega 2 = -179.7 degrees, phi 3 = 151.4 degrees, psi 3 = -151.9 degrees, omega 3 = -176.3 degrees. The pyrrolidine ring of the proline residue adopts the C2-C gamma conformation. The molecular packing gives rise to an antiparallel beta-sheet structure formed of dimeric repeating units of the peptide. The surface of the dimeric beta-sheet is hydrophobic. Water molecules are found systematically at the edges of the sheets interacting with the urethane oxygen and terminal amino groups. Surface catalysis of an L-Ala to D-Ala epimerization process by water molecules adsorbed on to an incipient beta-sheet is suggested as a mechanism whereby crystals of the title peptide were obtained from a solution of tBoc-Pro-D-Ala-Ala-NHCH3.
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Subramanian E, Sahayamary JJ. Structure and conformation of linear peptides. XIII. Structure of L-phenylalanyl-glycyl-glycine. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1989; 34:211-4. [PMID: 2599758 DOI: 10.1111/j.1399-3011.1989.tb00232.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The crystal structure of a tripeptide, L-phenylalanyl-glycyl-glycine (C13H17N3O4), molecular weight = 279.3, has been determined. The crystals are orthorhombic, space group P2(1)2(1)2(1), with a = 5.462(1) A, b = 15.285(5), c = 16.056(4), Z = 4, and P (calc) = 1.384 g.cm-3. The final R-index is 0.052 for 866 reflections with sin theta/lambda less than or equal to 0.55 A-1 and I greater than 1 sigma. The molecule exists as a zwitterion, with the N-terminus protonated and the C-terminus in an ionized form. Both the peptide units are in the trans configuration and planar, though one of them shows significant deviations from planarity ([delta w[ = 5.1 degrees). The peptide backbone is folded, with the torsion angles of: psi 1 = 116.2(5) degrees, omega 1 = 178.8(4), phi 2 = -89.7(5). psi 2 = -28.9(6), omega 2 = -174.9(4), phi 3 = 134.9(5), psi 31 = 7.8(6), psi 32 = -172.6(4). The terminal glycine adopts a "D-residue" conformation. For the sidechain of phenylalanine, chi 1 = 175.5(4), chi 2 = -127.0(6).
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Subramanian E, Sahayamary JJ. Structure and conformation of linear peptides. XII. Structure of tryptophanyl-glycyl-glycine dihydrate. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1989; 34:134-8. [PMID: 2807731 DOI: 10.1111/j.1399-3011.1989.tb01502.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The crystal structure of a tripeptide, tryptophanyl-glycyl-glycine dihydrate (C15H18N4O4.2H2O, molecular weight = 354) has been determined. The crystals are orthorhombic, space group P2(1)2(1)2(1), with a = 7.875 (1) A, b = 9.009(1), c = 24.307(1) and Z = 4. The final R-index is 0.058 for 1488 reflections [sin theta)/lambda less than or equal to 0.6 A-1) with I greater than 2 sigma (I). The molecule exists as a zwitterion, with terminal NH3+ and COO- groups. The peptide units are trans and nearly perpendicular to the plane of the carboxyl group. The backbone torsion angles are: psi 1 = 132.7 degrees, omega 1 = 174.2 degrees, phi 2 = 88.2 degrees, psi 2 = 8.6 degrees, omega 2 = -179.8 degrees, phi 3 = -85.2 degrees, psi 31 = -178.1 degrees, psi 32 = 5.0 degrees. For the sidechain of tryptophan, chi 1 = -171.6 degrees, chi 2 = 101.0 degrees.
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Maruthamuthu M, Subramanian E. pH-Dependent interaction of sulfamethoxazole with crosslinked poly(N-vinyl-2-pyrrolidone). Polym Bull (Berl) 1989. [DOI: 10.1007/bf00271974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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