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Environmental effects on the ultraviolet absorption spectrum of tyrosine

1966; Elsevier BV; Volume: 126; Issue: 1 Linguagem: Inglês

10.1016/0926-6585(66)90031-8

1878-2574

H. Grinspan, Jerome C. Birnbaum, Jehuda Feitelson,

Photochromic and Fluorescence Chemistry

The influence of a variety of mono- and polybasic alcohols, ethers and acids on the electronic absorption spectrum of tyrosine in aqueous solution was investigated. A shift towards longer wavelength in the first (Lb) and the second (La) band is observed as a function of solvent composition. The results are compared with those obtained for phenylalanine in similar solvent systems. It is found that the effects can be discussed in terms of hydrogen bond formation between tyrosine, acting as proton donor, and the various solvent components as proton acceptors. It is suggested that the changes in spectral properties due to hydrogen bonding may be attributed to a modification in the substituent effect of the hydroxyl group on the spectrum of the aromatic system. The implications of these effects in polypeptide conformation studies are briefly mentioned.