Photoswitching of Enzyme Activity by Laser-Induced pH-Jump

Abstract

Controlled initiation of biochemical events and in particular of protein activity is a powerful tool in biochemical research. Specifically, optical trigger signals are an attractive approach for remote control of enzyme activity. We present a method for generating optical control of enzyme activity applicable to a widespread range of enzymes. The approach is based on short laser pulses as optical "switches" introducing an instantaneous change of the pH-value for activation of protein function. The pH-jump is induced by proton release from 2-nitrobenzaldehyde. Reaction conditions were chosen to yield a pH-jump of almost 3 units on switching from inactive to active conditions for the enzyme. In this experimental setup, irradiation can be realized without any loss of enzyme activity. Following this change in pH-value, a controlled activation of hydrolytic activity of acid phosphatase is successfully demonstrated. This application provides a general method for photocontrol of enzymatic function for proteins having a significant pH-profile. The kinetic data for the substrate 6-chloro-8-fluoro-4-methylumbelliferone phosphate are determined.

Tightening up the structure, lighting up the pathway: application of molecular constraints and light to manipulate protein folding, self-assembly and function

“…While an in-depth summary [67, 129-132] of the recent advances in this field is beyond the scope of this Review, we would like to highlight several examples to underscore the rapid growth of this exciting research field. For instance, photoremovable protecting groups have been used to trigger acquisition of protein functions [133-135], to investigate enzyme binding and inhibition [136-138], protein translocation [139], chemotactic activity [140], peptide mediated lipid degradation [141], phosphopeptide-binding for signaling pathways [142, 143], and to regulate or control the function or activity of oligonucleotides [144, 145], neurotransmitters [146, 147], hormones [148], and signaling molecules [149, 150]. …”

Excited-State Hydroxide Ion Release From a Series of Acridinol Photobases

“…8 In addition to these basic studies of PT mechanism, the photoacids have also been applied to: (i) generate and characterize short-lived intermediates, such as H 2 CO 3 ; 10 (ii) probe the microenvironment of the biological systems (protein pockets and cells) [11][12][13][14][15][16][17] and other confined media (reverse micelles, cyclodextrins and nafion membranes); [18][19][20] (iii) study the protein folding kinetics using the pH jump technique. [21][22] In analogy to the photoacids described above, the photobases are defined here as compounds that release hydroxide ion (OH − ) upon excitation. Several types of photobases were identified in the '80s and were composed of triarylmethanol, xanthenol, fluorenol and other molecular frameworks.…”

Efficient Self‐Contained Photoacid Generator System Based on Photochromic Terarylenes

“…[1,2] Since the study of PAGs from 1970s, they have gained enormous interest and been widely used in the microlithographic technology [3][4][5] along with the explosive growth of semiconductor industry. Recently,t he applicationso fP AGs also extendedt oo ther domains such as photodynamic therapy, [6] photocontrolling of enzymatica ctivity, [7] and to photoinduced doping of conjugated polymers. [8][9][10] Remote activation of fluorescent molecules by photoacid generation [11] was also demonstrated with the view of super-resolution imaging [12] and imprinting of fluorescent patterns.…”