TY  - JOUR
A1  - Stauff, Joachim
A1  - Jaenicke, Rainer
A1  - Wolf, Heinrich
T1  - Über die Einwirkung von freien Sauerstoffradikalen auf Rinderserumalbumin in Lösung
T2  - Zeitschrift für Naturforschung, B
N2  - In order to determine the influence of OH and O2H-radicals on proteins, bovine serum albumin (BSA) in aqueous solution was treated with Fenton’s reagent [Fe(II)SO4+EDTA+H2O2] and with ultraviolet light (λ > 2800 Å) in the presence of H2O2. The action of free radicals produced in this way did not change the properties of the native protein with respect to the sedimentation in the ultracentrifuge or optical rotatory dispersion and electrophoresis under normal conditions. Ampèrometric titration indicated partial oxidation of SH-groups and of 3—5 SS-groups which are not reducible by NaBH4.
Heat aggregation investigated by means of light-scattering was suppressed at pH 7.5 and strongly accelerated at pH 4.6 (range of coagulation), the latter being a result of increased entropy of activation of coagulation velocity.
The difference spectrum against native BSA had positive values of Δε and two maxima at 2480 and 2950 Å.
Ultracentrifugation at room temperature in phosphate buffer (pH 7.3, μ=0.18) furnishes a molecular weight of 63 300. In a solution of 8 M urea and borate buffer (pH 9, μ=0.05) fragments with molecular weights between 25 000 and 37 000 were observed while in phosphate buffer (pH 7.3, without urea) at temperatures higher than 46 °C an anomalous behaviour of the concentration gradient indicated an effect which possibly depends on a dissociation equilibrium.
As a consequence oxygen radicals seem to attack not only SH- and SS-groups but at least one covalent bond of the peptide chain. Some experiments of heat aggregation with BSA treated with γ-rays (60Co) gave the same results as BSA treated with Fenton’s reagent or UV-light+H2O2.
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/71292
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-712926
SN  - 1865-7117
SN  - 0932-0776
VL  - 18.1963
IS  - 8
SP  - 618
EP  - 630
PB  - Verlag der Zeitschrift für Naturforschung
CY  - Tübingen
ER  -