Longitudinal diffusion behavior of hemicyanine dyes across phospholipid vesicle membranes as studied by second-harmonic generation and fluorescence spectroscopies

Yamaguchi, A.; Nakano, Masaki; Nochi, Kimihisa; Yamashita, Tomohisa; Morita, K.; Teramae, Norio

doi:10.1007/s00216-006-0470-x

Cited by 33 publications

(36 citation statements)

References 24 publications

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“…All these advantages of SHG have already been used to probe the diffusion of an aromatic compound across a biological membrane 8. 9 In this very specific application, it is in fact the decrease of the second harmonic signal that is followed, since in this case diffusion gives rise to oppositely oriented molecules at the inner part of the bilayer in comparison with molecules only being present at the outer surface.…”

Section: Introductionmentioning

confidence: 99%

Biocatalytic and Structural Properties of a Highly Engineered Halohydrin Dehalogenase

et al. 2013

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Two highly engineered halohydrin dehalogenase variants were characterized in terms of their performance in dehalogenation and epoxide cyanolysis reactions. Both enzyme variants outperformed the wild-type enzyme in the cyanolysis of ethyl (S)-3,4-epoxybutyrate, a conversion yielding ethyl (R)-4-cyano-3-hydroxybutyrate, an important chiral building block for statin synthesis. One of the enzyme variants, HheC2360, displayed catalytic rates for this cyanolysis reaction enhanced up to tenfold. Furthermore, the enantioselectivity of this variant was the opposite of that of the wild-type enzyme, both for dehalogenation and for cyanolysis reactions. The 37-fold mutant HheC2360 showed an increase in thermal stability of 8 °C relative to the wild-type enzyme. Crystal structures of this enzyme were elucidated with chloride and ethyl (S)-3,4-epoxybutyrate or with ethyl (R)-4-cyano-3-hydroxybutyrate bound in the active site. The observed increase in temperature stability was explained in terms of a substantial increase in buried surface area relative to the wild-type HheC, together with enhanced interfacial interactions between the subunits that form the tetramer. The structures also revealed that the substrate binding pocket was modified both by substitutions and by backbone movements in loops surrounding the active site. The observed changes in the mutant structures are partly governed by coupled mutations, some of which are necessary to remove steric clashes or to allow backbone movements to occur. The importance of interactions between substitutions suggests that efficient directed evolution strategies should allow for compensating and synergistic mutations during library design.

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Section: Introductionmentioning

confidence: 99%

Biocatalytic and Structural Properties of a Highly Engineered Halohydrin Dehalogenase

et al. 2013

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“…It was expected that the rate of transport across the CM should be similar to those obtained from prior liposome‐based studies . In both cases, the molecular probe has to directly diffuse across the lipid bilayer.…”

Section: Molecule—membrane Interactions Monitored With Second Harmonimentioning

confidence: 99%

“…Following this demonstration,anumber of studies have since examined the effects of lipid composition and av ariety of environmental factorso nt he propensity and characteristics of molecular transport across membranes in model liposome systems. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] The studies on liposomes suggested the feasibility that SHS could be used for monitoring molecular transport across membranesi nl iving biological cells. Indeed, in 2010, our laboratory reportedt he first demonstration that SHS could be applied to study molecular transport across membranes in living cells.…”

Section: Introductionmentioning

confidence: 99%

Molecule‐Membrane Interactions in Biological Cells Studied with Second Harmonic Light Scattering

Wilhelm

Dai

2019

Chemistry An Asian Journal

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The nonlinearo ptical phenomenon second harmonic light scattering (SHS) can be used for detecting molecules at the membrane surfaces of living biological cells. Over the last decade, SHS has been developed for quantitatively monitoring the adsorption and transport of smalla nd medium size molecules (both neutral and ionic) across membranes in living cells. SHS can be operated with both time and spatial resolution and is even capableo fisolating molecule-membrane interactions at specific membrane surfaces in multi-membrane cells, such as bacteria. In this review,w e discuss select examples from our lab employingt ime-resolved SHS to study real-time molecular interactions at the plasma membranes of biological cells. We first demonstrate the utility of this method for determining the transport rates at each membrane/interfacei naGram-negative bacterial cell. Next, we show how SHS can be used to characterize the molecular mechanism of the centuryo ld Gram stain protocol for classifyingb acteria. Additionally,w ee xamine how membrane structures and molecular charge and polarity affect adsorption and transport, as well as how antimicrobial compounds alter bacteria membrane permeability.F inally, we discuss adaptation of SHS as an imaging modality to quantify molecular adsorption and transport in sub-cellular regionso fi ndividual livingcells.[a] Prof.

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“…[7] All these advantages of SHG have already been used to probe the diffusion of an aromatic compound across a biological membrane. [8,9] In this very specific application, it is in fact the decrease of the second harmonic signal that is followed, since in this case diffusion gives rise to oppositely oriented molecules at the inner part of the bilayer in comparison with molecules only being present at the outer surface.…”

Section: Introductionmentioning

confidence: 97%

The Use of Second‐Harmonic Generation to Study Diffusion through Films under a Liquid Phase

et al. 2010

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Knowledge of the diffusion of chemicals through buried films is important for a wide variety of systems--from sensing to drug delivery. Herein, we show that second-harmonic generation (SHG) can be used to follow the diffusion through a thin film buried under a liquid in situ. More specifically, the diffusion of 4-(4-diethylaminostyryl)-1-methylpyridinium iodide through zeolite precursor films of different thickness is followed. The diffusion coefficients are calculated according to Fick's law.

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Longitudinal diffusion behavior of hemicyanine dyes across phospholipid vesicle membranes as studied by second-harmonic generation and fluorescence spectroscopies

Cited by 33 publications

References 24 publications

Biocatalytic and Structural Properties of a Highly Engineered Halohydrin Dehalogenase

Biocatalytic and Structural Properties of a Highly Engineered Halohydrin Dehalogenase

Molecule‐Membrane Interactions in Biological Cells Studied with Second Harmonic Light Scattering

The Use of Second‐Harmonic Generation to Study Diffusion through Films under a Liquid Phase

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