Sorption equilibrium and hydration studies of lysozyme: water activity and 360-MHz proton NMR measurement

Journal Article · · J. Agric. Food Chem.; (United States)

DOI:https://doi.org/10.1021/jf00073a029· OSTI ID:6601963

Lioutas, T S; Baianu, I C; Steinberg, M P

An attempt to determine lysozyme hydration by employing a proton nuclear magnetic resonance (NMR) spin-echo technique and to correlated such measurements with the 20 /sup 0/C sorption equilibrium data is made. Determinations of specific site hydration for lysozyme, as well as proton NMR transverse relaxation rates for five different types of water populations in the lysozyme-water system, are presented over the whole range of lysozyme concentrations. The proton spin-echo NMR results are consistent with a three-component analysis of the sorption isotherm up to 70% water content, above which two additional water populations are identified by 360-MHz proton NMR spin-echoes. On the basis of the proton NMR results, a major component (III) of the lysozyme sorption isotherm is assigned to the water trapped between lysozyem molecules, whose relaxation rate is increased by diffusion barriers. The trapped water population dominates the relationship between the relative vapor pressure of hydrated lysozyme and the corresponding, transverse proton NMR relaxation rates.

• Research Organization: Univ. of Illinois, Urbana-Champaign
• OSTI ID: 6601963
• Journal Information: J. Agric. Food Chem.; (United States), Journal Name: J. Agric. Food Chem.; (United States) Vol. 35:1; ISSN JAFCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101 -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
553000* -- Agriculture & Food Technology
60 APPLIED LIFE SCIENCES
ADSORPTION ISOTHERMS
BARYONS
ELEMENTARY PARTICLES
ENZYMES
FERMIONS
FOOD
GLYCOSYL HYDROLASES
HADRONS
HYDRATION
HYDROLASES
ISOTHERMS
LYSOZYME
MAGNETIC RESONANCE
MOLECULES
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEONS
O-GLYCOSYL HYDROLASES
PHYSICAL PROPERTIES
PROTONS
RESONANCE
SOLVATION
SPECTRA
SPIN ECHO
THERMODYNAMIC PROPERTIES
VAPOR PRESSURE