Comparative 1H-NMR studies on the physical state of water in soft contact lens and mouse lens.
The physical state of water in mouse lenses (2-, 4- or 8-wk-old) and soft contact lenses (SCLs, water content from 18.4 to 79.2%) were studied by measuring spin-lattice relaxation times (T1) and apparent intermolecular cross-relaxation times (TIS) from irradiated protein or polymer protons to water protons, using 360 MHz 1H-NMR spectrometer at 25 degrees C. (1) 1/T1 values of SCLs increased gradually with increasing dry weight (W(%)). 1/TIS values of SCLs were approximately zero at W of 20.8 and 26.8%, increased gradually from 26.8% and then steeply above approximately 50%. (2) A plot of 1/T1 vs. W(%) of mouse lenses was almost equal to that of SCLs. However, a plot of 1/TIS vs. W(%) was an approximately straight line with the intercept at W of 23% and with the slope which is almost equal to that of SCLs above W of approximately 50%. The plot of 1/TIS vs. W(%) of mouse lenses might indicate the significant change in the physical state of water and/or protein-water interactions above W of 23%.
Kuwata
K
K
Department of Physiology, Gifu University School of Medicine, Japan.
Era
S
S
Sogami
M
M
Amano
H
H
Nagaoka
S
S
Kato
K
K
Takahashi
K
K
Kitazawa
Y
Y
Watari
H
H
D000367:Age Factors; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003263:Contact Lenses, Hydrophilic; D003459:Crystallins / Q000737:chemistry; D006801:Humans; D007908:Lens, Crystalline / Q000737:chemistry*; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry; D011522:Protons; D014867:Water / Q000737:chemistry*
D003459:Crystallins; D046911:Macromolecular Substances; D011108:Polymers; D011522:Protons; D014867:Water