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David E. Wemmer - One of the best experts on this subject based on the ideXlab platform.

  • three dimensional structure of soybean trypsin chymotrypsin bowman birk inhibitor in solution
    1993
    Co-Authors: Milton H Werner, David E. Wemmer
    Abstract:

    The three-dimensional structure of soybean trypsin/chymotrypsin Bowman-Birk inhibitor in solution has been determined by two-dimensional 1H nuclear magnetic resonance spectroscopy and dynamical simulated annealing using the program XPLOR. The structure was defined by 907 NOEs involving intra- and interresidue contacts which served as distance constraints for a protocol of dynamical simulated annealing. In addition, 48 phi angle constraints involving non-proline amino acids, 29 chi angle constraints, six omega angle constraints for the X-Pro peptide bond, and 35 stereoassignments for prochiral centers were incorporated during the course of the calculation. The protein is characterized by two distinct binding domains for serine protease. Each domain is comprised of a beta-hairpin (Antiparallel Beta-Sheet and a cis-proline-containing type VIb reverse turn) with a short segment making a third strand of Antiparallel Beta-Sheet. The structure determination and refinement are described, and the structure is compared to other structures of Bowman-Birk inhibitors as well as other families of serine protease inhibitors.

  • 1h assignments and secondary structure determination of the soybean trypsin chymotrypsin bowman birk inhibitor
    1991
    Co-Authors: Milton H Werner, David E. Wemmer
    Abstract:

    The {sup 1}H resonance assignments and secondary structure of the trypsin/chymotrypsin Bowman-Birk inhibitor from soybeans were determined by nuclear magnetic resonance spectroscopy (NMR) at 600 MHz in an 18% acetonitrile-d{sub 3}/aqueous cosolvent. Resonances from 69 to 71 amino acids were assigned sequence specifically. Residues Q11-T15 form an Antiparallel {beta}-sheet with residues Q21-S25 in the tryptic inhibitory domain and an analogous region of Antiparallel sheet forms between residues S38-A42 and Q48-V52 in the chymotryptic inhibitory domain. The inhibitory sites of each fragment (K16-S17 for trypsin, L43-S44 for chymotrypsin) are each part of a type VI like turn at one end of their respective region of the Antiparallel {beta}-sheet. These structural elements are compared to those found in other Bowman-Birk inhibitors.

Milton H Werner - One of the best experts on this subject based on the ideXlab platform.

  • three dimensional structure of soybean trypsin chymotrypsin bowman birk inhibitor in solution
    1993
    Co-Authors: Milton H Werner, David E. Wemmer
    Abstract:

    The three-dimensional structure of soybean trypsin/chymotrypsin Bowman-Birk inhibitor in solution has been determined by two-dimensional 1H nuclear magnetic resonance spectroscopy and dynamical simulated annealing using the program XPLOR. The structure was defined by 907 NOEs involving intra- and interresidue contacts which served as distance constraints for a protocol of dynamical simulated annealing. In addition, 48 phi angle constraints involving non-proline amino acids, 29 chi angle constraints, six omega angle constraints for the X-Pro peptide bond, and 35 stereoassignments for prochiral centers were incorporated during the course of the calculation. The protein is characterized by two distinct binding domains for serine protease. Each domain is comprised of a beta-hairpin (Antiparallel Beta-Sheet and a cis-proline-containing type VIb reverse turn) with a short segment making a third strand of Antiparallel Beta-Sheet. The structure determination and refinement are described, and the structure is compared to other structures of Bowman-Birk inhibitors as well as other families of serine protease inhibitors.

  • 1h assignments and secondary structure determination of the soybean trypsin chymotrypsin bowman birk inhibitor
    1991
    Co-Authors: Milton H Werner, David E. Wemmer
    Abstract:

    The {sup 1}H resonance assignments and secondary structure of the trypsin/chymotrypsin Bowman-Birk inhibitor from soybeans were determined by nuclear magnetic resonance spectroscopy (NMR) at 600 MHz in an 18% acetonitrile-d{sub 3}/aqueous cosolvent. Resonances from 69 to 71 amino acids were assigned sequence specifically. Residues Q11-T15 form an Antiparallel {beta}-sheet with residues Q21-S25 in the tryptic inhibitory domain and an analogous region of Antiparallel sheet forms between residues S38-A42 and Q48-V52 in the chymotryptic inhibitory domain. The inhibitory sites of each fragment (K16-S17 for trypsin, L43-S44 for chymotrypsin) are each part of a type VI like turn at one end of their respective region of the Antiparallel {beta}-sheet. These structural elements are compared to those found in other Bowman-Birk inhibitors.

H S Chung - One of the best experts on this subject based on the ideXlab platform.

  • two dimensional infrared spectroscopy of Antiparallel beta sheet secondary structure
    2004
    Co-Authors: N Demirdoven, C M Cheatum, H S Chung, Munira Khalil, Jasper Knoester, Andrei Tokmakoff
    Abstract:

    We investigate the sensitivity of femtosecond Fourier transform two-dimensional infrared spectroscopy to protein secondary structure with a study of Antiparallel β-sheets. The results show that 2D IR spectroscopy is more sensitive to structural differences between proteins than traditional infrared spectroscopy, providing an observable that allows comparison to quantitative models of protein vibrational spectroscopy. 2D IR correlation spectra of the amide I region of poly-l-lysine, concanavalin A, ribonuclease A, and lysozyme show cross-peaks between the IR-active transitions that are characteristic of amide I couplings for polypeptides in Antiparallel hydrogen-bonding registry. For poly-l-lysine, the 2D IR spectrum contains the eight-peak structure expected for two dominant vibrations of an extended, ordered Antiparallel β-sheet. In the proteins with Antiparallel β-sheets, interference effects between the diagonal and cross-peaks arising from the sheets, combined with diagonally elongated resonances from...

Jean Marie Ruysschaert - One of the best experts on this subject based on the ideXlab platform.

  • Antiparallel beta sheet a signature structure of the oligomeric amyloid beta peptide
    2009
    Co-Authors: Emilie Cerf, Rabia Sarroukh, Leonid Breydo, Sylvie Derclaye, Yves F. Dufrêne, Vasanthy Narayanaswami, Erik Goormaghtigh, Shiori Tamamizukato, Jean Marie Ruysschaert
    Abstract:

    AD (Alzheimer's disease) is linked to Abeta (amyloid beta-peptide) misfolding. Studies demonstrate that the level of soluble Abeta oligomeric forms correlates better with the progression of the disease than the level of fibrillar forms. Conformation-dependent antibodies have been developed to detect either Abeta oligomers or fibrils, suggesting that structural differences between these forms of Abeta exist. Using conditions which yield well-defined Abeta-(1-42) oligomers or fibrils, we studied the secondary structure of these species by ATR (attenuated total reflection)-FTIR (Fourier-transform infrared) spectroscopy. Whereas fibrillar Abeta was organized in a parallel Beta-Sheet conformation, oligomeric Abeta displayed distinct spectral features, which were attributed to an Antiparallel Beta-Sheet structure. We also noted striking similarities between Abeta oligomers spectra and those of bacterial outer membrane porins. We discuss our results in terms of a possible organization of the Antiparallel Beta-Sheets in Abeta oligomers, which may be related to reported effects of these highly toxic species in the amyloid pathogenesis associated with AD.

  • Antiparallel Beta-Sheet: a signature structure of the oligomeric amyloid beta-peptide
    2009
    Co-Authors: Emilie Cerf, Rabia Sarroukh, Shiori Tamamizu-kato, Leonid Breydo, Sylvie Derclaye, Yves F. Dufrêne, Vasanthy Narayanaswami, Erik Goormaghtigh, Jean Marie Ruysschaert, Vincent Raussens
    Abstract:

    AD (Alzheimer's disease) is linked to A beta (amyloid beta-peptide) misfolding. Studies demonstrate that the level Of Soluble A beta oligomeric forms correlates better with the progression of the disease than the level of fibrillar forms. Conformation-dependent antibodies have been developed to detect either A beta oligomers or fibrils, suggesting that structural differences between these forms of At exist. Using conditions which yield well-defined A beta (1-42) oligomers or fibrils, We studied the secondary structure of these species by ATR (attenuated total reflection)-FTIR (Fourier-transform infrared) spectroscopy. Whereas fibrillar A beta was organized in a parallel Beta-Sheet conformation, oligomeric A beta displayed distinct spectral features, which were attributed to an Antiparallel Beta-Sheet structure. We also noted striking similarities between A beta oligomers spectra and those of bacterial outer membrane porins. We discuss our results in terms of a possible organization of the Antiparallel Beta-Sheets in A beta oligomers, which may be related to reported effects of these highly toxic species in the amyloid pathogenesis associated with AD.

Vasanthy Narayanaswami - One of the best experts on this subject based on the ideXlab platform.

  • Antiparallel beta sheet a signature structure of the oligomeric amyloid beta peptide
    2009
    Co-Authors: Emilie Cerf, Rabia Sarroukh, Leonid Breydo, Sylvie Derclaye, Yves F. Dufrêne, Vasanthy Narayanaswami, Erik Goormaghtigh, Shiori Tamamizukato, Jean Marie Ruysschaert
    Abstract:

    AD (Alzheimer's disease) is linked to Abeta (amyloid beta-peptide) misfolding. Studies demonstrate that the level of soluble Abeta oligomeric forms correlates better with the progression of the disease than the level of fibrillar forms. Conformation-dependent antibodies have been developed to detect either Abeta oligomers or fibrils, suggesting that structural differences between these forms of Abeta exist. Using conditions which yield well-defined Abeta-(1-42) oligomers or fibrils, we studied the secondary structure of these species by ATR (attenuated total reflection)-FTIR (Fourier-transform infrared) spectroscopy. Whereas fibrillar Abeta was organized in a parallel Beta-Sheet conformation, oligomeric Abeta displayed distinct spectral features, which were attributed to an Antiparallel Beta-Sheet structure. We also noted striking similarities between Abeta oligomers spectra and those of bacterial outer membrane porins. We discuss our results in terms of a possible organization of the Antiparallel Beta-Sheets in Abeta oligomers, which may be related to reported effects of these highly toxic species in the amyloid pathogenesis associated with AD.

  • Antiparallel Beta-Sheet: a signature structure of the oligomeric amyloid beta-peptide
    2009
    Co-Authors: Emilie Cerf, Rabia Sarroukh, Shiori Tamamizu-kato, Leonid Breydo, Sylvie Derclaye, Yves F. Dufrêne, Vasanthy Narayanaswami, Erik Goormaghtigh, Jean Marie Ruysschaert, Vincent Raussens
    Abstract:

    AD (Alzheimer's disease) is linked to A beta (amyloid beta-peptide) misfolding. Studies demonstrate that the level Of Soluble A beta oligomeric forms correlates better with the progression of the disease than the level of fibrillar forms. Conformation-dependent antibodies have been developed to detect either A beta oligomers or fibrils, suggesting that structural differences between these forms of At exist. Using conditions which yield well-defined A beta (1-42) oligomers or fibrils, We studied the secondary structure of these species by ATR (attenuated total reflection)-FTIR (Fourier-transform infrared) spectroscopy. Whereas fibrillar A beta was organized in a parallel Beta-Sheet conformation, oligomeric A beta displayed distinct spectral features, which were attributed to an Antiparallel Beta-Sheet structure. We also noted striking similarities between A beta oligomers spectra and those of bacterial outer membrane porins. We discuss our results in terms of a possible organization of the Antiparallel Beta-Sheets in A beta oligomers, which may be related to reported effects of these highly toxic species in the amyloid pathogenesis associated with AD.