Effects of molecular association on structure and dynamics of a collagenous peptide.
Effects of molecular association on structure and dynamics of a collagenous peptide.
复制标题
分子缔合对胶原肽结构和动力学的影响。
DOI：
10.1002/bip.360330403
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发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Mayo,KH
中科院分区：
文献类型：
--
作者：
Daragan,VA;Ilyina,E;Mayo,KH
Peptide GVKGDKGNPGWPGAPY from the triple‐helix domain of type IV collagen aggregates in solution at a critical aggregation concentration of 18 mM. This molecular self association process is investigated by1H‐ and13C‐nmr spectroscopy. As a function of increasing peptide concentration, selective1H resonances are cooperatively chemically shifted by up to 0.04 ppm to apparently saturable values at high concentration. Pulsed field gradient nmr was used to derive translation diffusion constants that, as the peptide concentration is increased, also cooperatively and monotonically decrease to an apparent limiting value. An average number of 6 monomer units per aggregate have been estimated from diffusion constant and13C relaxation data. Comparative1H nuclear Overhauser effect spectroscopy (NOESY) spectra accumulated at high and low peptide concentrations suggest that average internuclear distances are decreased as a result of peptide association.13C‐nmr multiplet spin‐lattice relaxation and13C‐ {1H} NOE effects on13C‐enriched glycine methylene positions in the peptide demonstrate that overall molecular tumbling and backbone internal motions are attenuated in the aggregate state. Lowering the solution pD from pD 6 to pD 2 disrupts the aggregate state, suggesting a role for electrostatic interactions in the association process. Based on thermodynamic considerations, hydrophobic interactions also probably act to stabilize the aggregate state. These data are discussed in terms of an nmr/NOE constrained computer‐modeled structure of the peptide. © 1993 John Wiley & Sons, Inc.
