Solid-state proton relaxation of biomolecular components

摘要: Abstract A proton magnetic relaxation study has been carried out on a series of biomolecular components in the solid state range 50 to 500 K. In family twenty amino acids encountered proteins, reorientation NH3 group zwitterion form molecules provides an effective source all except arginine and proline. Reorientation methyl groups, where present side chains, second resolved at lower temperatures. Additional motions are cysteine phenylalanine. mechanism diglycine triglycine, as glycine itself, although reorienting progressively more protons relax until polyglycine its effect is weak. Well-resolved minima glycyl- l -alanine -alanylglycine attributed independent CH3 groups these dipeptides. Activation energies, constants, other parameters characterizing derived compared. First results presented solid-state enzyme lysozyme, along popypeptide chain probable chief relaxation. distribution correlation times evident. The five nucleic acid bases have examined. thymine generates well-defined minimum. absence three DNA bases-adenine, cytosine, guanine-and uracil, leads much longer times. evidently strongly hindered. Preliminary measurements calf thymus suggest importance sources