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oai:www.ideals.illinois.edu:2142/23543 2023-07-10 col_2142_5131 col_2142_14781 com_2142_5130 com_2142_687 com_2142_397

Baianu, Ion C. Kakalis, Lazaros Thomas 2011-05-07T14:18:06Z 2011-05-07T14:18:06Z 10000-01-01 1989 The potential of high-resolution $\sp{13}$C NMR for the characterization of soybean storage proteins was explored. The spectra of a commercial soy protein isolate as well as those of alkali-denatured 7S and 11S soybean globulins were well resolved and tentatively assigned. Relaxation measurements indicated fast motion for several side chains and the protein backbone. Protein fractions (11S and 7S) were also investigated at various states of molecular association. The large size of the multisubunit soybean storage proteins affected adversely both the resolution and the sensitivity of their $\sp{13}$C NMR spectra. A comparison of $\sp{17}$O and $\sp2$H NMR relaxation rates of water in solutions of lysozyme (a model system) as a function of concentration, pH and magnetic field suggested that only $\sp{17}$O monitors directly the hydration of lysozyme. Analysis of $\sp{17}$O NMR lysozyme hydration data in terms of a two-state, fast-exchange, anisotropic model resulted in hydration parameters which are consistent with the protein's physico-chemical properties. The same model was applied to the calculation of the amount and mobility of 'bound' water in soy protein dispersions by means of $\sp{17}$O NMR relaxation measurements as a function of protein concentration. The protein concentration dependences of $\sp1$H transverse NMR relaxation measurements at various pH and ionic strength values were fitted by a virial expansion. The interpretation of the data was based on the effects of protein aggregation, salt binding and protein group ionization on the NMR measurements. In all cases, relaxation rates showed a linear dependence on protein activity. Made available in DSpace on 2011-05-07T14:18:06Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9010906.pdf: 6071314 bytes, checksum: 8831c2e18818b1933e26e0cfc893f2ac (MD5) Previous issue date: 1989 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:05:11Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:31:12-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9010906 (UMI)AAI9010906 http://hdl.handle.net/2142/23543 eng Copyright 1989 Kakalis, Lazaros Thomas Agriculture, Food Science and Technology Chemistry, Physical Biophysics, General Molecular structure, dynamics and hydration studies of soybean storage proteins and model systems by nuclear magnetic resonance text Agriculture, Food Science and Technology Chemistry, Physical Biophysics, General Agriculture, Food Science and Technology Chemistry, Physical Biophysics, General University of Illinois at Urbana-Champaign Dissertation Ph.D.