| 摘 要： | Examples of some important biophysical,biochemical and biomedical problems that have been uniquely solved by Raman spectroscopy will be illustrated and discussed.The first example concerns the electronic structure,metal-ligand bonding,and reactivity of metalloporphyrins,the synthetic models for the ubiquitous chromophore in hemoproteins.we will demonstrate how off-resonance scattering,electronic resonance enhanced scattering,as well as nonlinear hyper-Raman(three-photon)scattering can provide a highly complementary picture about the effective electronic symmetry and bonding of metalloporphyrins in its electronic ground and excited states.we will illustrate how the bonding information otained from the Raman effect can be useful in understanding the chemical behavior of metalloporhyrin such as its affinity toward exogenous ligand and its preference for the orientation of planar axial ligand(such as imidazole from histidine‘s sidechain).Some paradoxical misconception about the relationship between bond strength and ligand binding affinity will be discussed.Raman spectroscopy,particular with near infraed laser excitation to avoid fluorescence,has been applied successfully to extract significant biochemical information from intact eye lenses.The long-standing cotroversy over the exact nature of the involvement of disulfide cross-linking in lens aging and cataract formation has been settled by the Raman spectroscopy because of its ability for monitoring the sulfhydryl to disulfide reaction of an intact lens in a nondestructive and noninvasive manner.A more recent contribution to the lens biochemistry is the use of Raman spectroscopy for a clear demonstration of the biochemical changes induced by near ultraviolet light in the lens of an animal model,resembling the changes observed in human lens aging and cataract formation.
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