Analyzing the red-shift characteristics of azulenic, naphthyl, other ring-fused and retinyl pigment analogs of bacteriorhodopsin
| Autor: | Erik Krogh, Leticia U. Colmenares, Dennis Mead, Darren Wong, J.R. Thiel, Jeannette Ellis, Robert S. H. Liu, Alfred E. Asato, Xiaoyuan Li |
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| Rok vydání: | 1993 |
| Předmět: |
Models
Molecular Opsin Magnetic Resonance Spectroscopy Stereochemistry Protonation Naphthalenes Biochemistry Azulenes Absorption chemistry.chemical_compound Pigment Computer Simulation Physical and Theoretical Chemistry Cycloheptanes Schiff Bases biology Retinal Bacteriorhodopsin General Medicine Nuclear magnetic resonance spectroscopy Chromophore chemistry Spectrophotometry visual_art Bacteriorhodopsins Retinaldehyde biology.protein visual_art.visual_art_medium Protein Binding |
| Zdroj: | Photochemistry and photobiology. 58(5) |
| ISSN: | 0031-8655 |
| Popis: | Prompted by the near infrared-absorbing properties of some of the azulenic bacteriorhodopsin (bR) analogs, we have analyzed their absorption characteristics along with 11 new related ring-fused analogs and the corresponding Schiff bases (SB) and protonated Schiff bases (PSB). The following three factors are believed to contribute to the total red shift of each of the pigment analogs (sigma RS): perturbation of the basic chromophore (SB shift, delta SB), protonation of the SB (PSB shift, PSBS) and protein perturbation (the opsin shift, OS). For each factor, effects of structural modifications were examined. For the red-shifted pigments, percent OS has been suggested as an alternate way of measuring protein perturbation. Computer-simulated chromophores provided evidence against any explanation involving altered shapes of the binding pocket as a major cause for absorption differences. Implications of the current bR results on preparation of further red-shifted bR and possible application to visual pigment analogs are discussed. |
| Databáze: | OpenAIRE |
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