Using 1-(2-nitrophenyl)ethyl sulfate (caged sulfate) as a photoactivatable caged proton, we could induce complete acid unfolding of myoglobin with a single nanosecond laser pulse. This was possible because of the high (≈ mM) concentration of protons released by the photolabile compound. The ability of the compound to produce a large pH jump arises because the other photoproducts (2-nitrosoacetophenone and sulfate ion) do not buffer the released protons. The complete time course of the unfolding kinetics, spanning a range from milliseconds to several seconds, could be accurately reproduced by monitoring absorbance changes in the visible spectrum at 633 nm.
Acid-induced unfolding of myoglobin triggered by a laser pH jump method / Abbruzzetti, Stefania; S., Sottini; Viappiani, Cristiano; J. E. T., Corrie. - In: PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES. - ISSN 1474-905X. - 5:(2006), pp. 621-628. [10.1039/b516533d]
Acid-induced unfolding of myoglobin triggered by a laser pH jump method
ABBRUZZETTI, Stefania;VIAPPIANI, Cristiano;
2006-01-01
Abstract
Using 1-(2-nitrophenyl)ethyl sulfate (caged sulfate) as a photoactivatable caged proton, we could induce complete acid unfolding of myoglobin with a single nanosecond laser pulse. This was possible because of the high (≈ mM) concentration of protons released by the photolabile compound. The ability of the compound to produce a large pH jump arises because the other photoproducts (2-nitrosoacetophenone and sulfate ion) do not buffer the released protons. The complete time course of the unfolding kinetics, spanning a range from milliseconds to several seconds, could be accurately reproduced by monitoring absorbance changes in the visible spectrum at 633 nm.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.