Acid-induced unfolding of myoglobin triggered by a laser pH jump method.
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 ( approximately 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.
Abbruzzetti
Stefania
S
Dipartimento di Fisica, Università degli Studi di Parma, Parco Area delle Scienze 7/A, 43100 Parma, Italy.
Sottini
Silvia
S
Viappiani
Cristiano
C
Corrie
John E T
JE
D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007834:Lasers; D009211:Myoglobin / Q000737:chemistry*; D011489:Protein Denaturation
D009211:Myoglobin