Volume and Enthalpy Changes of Proton Transfers in the Bacteriorhodopsin Photocycle Studied by Millisecond Time-Resolved Photopressure Measurements

Liu, Yan; Edens, Gregory J.; Grzymski, Joseph J.; Mauzerall, D.

doi:10.1021/bi800158x

Cited by 9 publications

(4 citation statements)

References 56 publications

(96 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The phenomenon of PPT is widely observed in natural systems, such as in bacteriorhodopsin . In recent times, artificial PPT processes, as observed in photoacid/dye systems, have been utilized in the fabrication of light-responsive color-switching materials. , Visible light serves as the input, transforming a conventional acid-initiated chemical process into a controllable photochemical reaction without the need for additional chemicals, while exhibiting excellent reversibility .…”

Section: Resultsmentioning

confidence: 99%

Customizable High-Contrast Optical Responses: Dual Photosensitive Colors for Smart Textiles

Fan,

Wu,

Liu

et al. 2023

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Smart textiles demonstrating optical responses to external light stimuli hold great promise as functional materials with a wide range of applications in personalized decoration and information visualization. The incorporation of high-contrast, vivid, and real-time optical signals, such as color change or fluorescence emission, to indicate light on/off states is both crucial and challenging. In this study, we have developed a dual output photosensitive dye system possessing photochromic and photofluorescent properties, which was successfully applied to the dyeing and finishing processes of cotton fabrics. The design and fabrication of this dye system were based on the unique photoinduced proton transfer (PPT) principle exhibited by the water-soluble spiropyran (trans-MCH) molecule. The dual output response relies on the open-/closed-loop mechanism, wherein light regulates the trans-MCH molecule. Upon excitation by UV or visible light, the dye system and dyed fabrics display significant color changes and fluorescence switching in a real-time and highly reversible manner. Moreover, diverse photosensitive color systems can be tailored by direct blending with commercially available water-soluble dyes. By integrating high-contrast dual optical outputs into this scalable, versatile, and reversible dye system, we envisage the development and design of smart textiles capable of producing high-end products.

show abstract

Section: Resultsmentioning

confidence: 99%

Customizable High-Contrast Optical Responses: Dual Photosensitive Colors for Smart Textiles

Fan,

Wu,

Liu

et al. 2023

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…Recently, using photothermal beam deflection techniques the enthalpies of PS II water oxidation were reported [94]. Using a novel photopressure cell that enables one to obtain the volume and enthalpy changes on the microsecond to second time scales [21], the thermodynamic parameter of reactions involved in PS II oxygen evolution might be determined.…”

Section: Discussionmentioning

confidence: 99%

Methodology of Pulsed Photoacoustics and Its Application to Probe Photosystems and Receptors

Hou

Sakmar

2010

Sensors

View full text Add to dashboard Cite

We review recent advances in the methodology of pulsed time-resolved photoacoustics and its application to studies of photosynthetic reaction centers and membrane receptors such as the G protein-coupled receptor rhodopsin. The experimental parameters accessible to photoacoustics include molecular volume change and photoreaction enthalpy change. Light-driven volume change secondary to protein conformational changes or electrostriction is directly related to the photoreaction and thus can be a useful measurement of activity and function. The enthalpy changes of the photochemical reactions observed can be measured directly by photoacoustics. With the measurement of enthalpy change, the reaction entropy can also be calculated when free energy is known. Dissecting the free energy of a photoreaction into enthalpic and entropic components may provide critical information about photoactivation mechanisms of photosystems and photoreceptors. The potential limitations and future applications of time-resolved photoacoustics are also discussed.

show abstract

“…Thus a positive volume due to a protein conformational change may be possible. The volume changes (+30 to +70 Å 3 ) due to protein conformational changes were observed in the photoreaction of bacteriorhodopsin and rhodopsin ,, .…”

Section: Discussionmentioning

confidence: 99%

Thermodynamics of Charge Separation of Photosystem I in the menA and menB Null Mutants of Synechocystis sp. PCC 6803 Determined by Pulsed Photoacoustics

et al. 2009

Self Cite

View full text Add to dashboard Cite

When the biosynthesis of phylloquinone is inhibited in Synechocystis sp. PCC 6803 by interrupting the menA or the menB gene, photosystem I (PS I) recruits plastoquinone-9 (A(P)) to occupy the A(1) sites. In PS I from the menA and menB null mutants, forward electron transfer from the quinone to the FeS clusters occurs approximately 1000 times slower than in wild-type PS I [Semenov, A. Yu., Vassiliev, I. R., van der Est, A., Mamedov, M. D., Zybailov, B., Shen, G., Stehlik, D., Diner, B. A., Chitnis, P. R., and Golbeck, J. H. (2000) J. Biol. Chem. 275, 23429-23438]. To investigate the effect on thermodynamics, the enthalpy and volume changes of charge separation in PS I in the menA and menB mutants were measured using pulsed time-resolved photoacoustics on the nanosecond and microsecond time scales. The observed thermodynamic data are the same for the menA and menB mutants. This is expected because the recruited quinone (A(P)) is the same in both mutants. The volume change of PS I from the mutants following charge separation on both time scales was -17 +/- 2 A(3), less than that of the wild type, -21 A(3). The quantum yield of charge separation was found to be slightly lower (85 +/- 9%) than that of wild-type PS I (96 +/- 10%). The observed reaction is assigned to the formation of P(700)(+)A(P)(-) from P(700)*A(P). An enthalpy change (DeltaH) of -0.69 +/- 0.07 eV was obtained for this reaction. In contrast, a larger enthalpy change -0.8 eV for the formation of P(700)(+)A(1)(-) from P(700)* and an apparent entropy change (TDeltaS, T = 25 degrees C) of -0.2 eV were obtained in wild-type PS I [Hou, H. J. M., and Mauzerall, D. (2006) J. Am. Chem. Soc. 128, 1580-1586]. Taking the free energy to be -0.70 eV in PS I of the mutants, the apparent entropy is close to zero in the mutants. Since the apparent entropy change for the overall reaction of the production of P(700)(+)F(A/B)(-) from P(700)* is very likely the same as that of the wild type, +0.35 eV, this implies that the reaction of P(700)(+)A(P)(-)F(A/B) --> P(700)(+)A(P)F(A/B)(-) in the mutants is almost completely entropy driven (DeltaG = -0.07 eV and TDeltaS = +0.40 eV). These results show that not only the kinetics but also the thermodynamics of electron transfer reactions in PS I are significantly affected by the recruitment of the foreign plastoquinone-9 into the A(1) site.

show abstract

Volume and Enthalpy Changes of Proton Transfers in the Bacteriorhodopsin Photocycle Studied by Millisecond Time-Resolved Photopressure Measurements

Cited by 9 publications

References 56 publications

Customizable High-Contrast Optical Responses: Dual Photosensitive Colors for Smart Textiles

Customizable High-Contrast Optical Responses: Dual Photosensitive Colors for Smart Textiles

Methodology of Pulsed Photoacoustics and Its Application to Probe Photosystems and Receptors

Thermodynamics of Charge Separation of Photosystem I in the menA and menB Null Mutants of Synechocystis sp. PCC 6803 Determined by Pulsed Photoacoustics

Contact Info

Product

Resources

About