Structural damage in γ-irradiated lysozyme
| Autor: | Bert M. Tolbert, Dante J. Marciani |
|---|---|
| Rok vydání: | 1974 |
| Předmět: |
Protein Conformation
Hydrochloride Peptide Tritium Guanidines Biochemistry Genetics and Molecular Biology (miscellaneous) Micrococcus chemistry.chemical_compound Egg White Irradiation Guanidine chemistry.chemical_classification Binding Sites Tryptophan Water Dose-Response Relationship Radiation Hydrogen-Ion Concentration Chromophore Chromatography Ion Exchange Protein tertiary structure Radiation Effects Kinetics Solubility chemistry Biochemistry Chromatography Gel Biophysics Muramidase Spectrophotometry Ultraviolet Lysozyme Protein Binding |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Protein Structure. 351:387-395 |
| ISSN: | 0005-2795 |
| DOI: | 10.1016/0005-2795(74)90203-7 |
| Popis: | The distribution of the different kinetic classes of exchangeable hydrogens have been measured for γ-irradiated lysozyme (mucopeptide N -acetylmuramylhydrolase, EC 3.4.1.17). Class I hydrogen, associated with fully exposed structures, did not show significant alterations as a function of radiation dose. Class II hydrogen, associated with relatively unhindered peptide groups, showed an increase which is function of radiation doses. Class III and IV hydrogen presented an almost equal rate of decrease that is exponentially related to the dose. The decrease of Class III and IV hydrogens seems to indicate a disruption of structures such as α-helical and β-structures, and destruction of hydrophobic regions which maintain the tertiary structure of the protein. Difference-spectra studies corroborate these results, presenting the more damaged fractions a higher degree of tryptophan exposure as compared to native lysozyme. Spectroscopic studies in presence of guanidine hydrochloride have revealed new chromophore(s) group which seems to be originated from tryptophan. The relationship between the damage of hydrophobic groups and structural damage is discussed. |
| Databáze: | OpenAIRE |
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