Tag Archives: gold coated PointProbe Plus AFM tips

Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2

Engineering chlorophyll (Chl) pigments that are bound to photosynthetic light-harvesting proteins is one promising strategy to regulate spectral coverage for photon capture and to improve the photosynthetic efficiency of these proteins.*

The in situ oxidation of BChl a in light-harvesting protein LH2 from a purple bacterium Rhodoblastus acidophilus by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone demonstrated in the article “Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2” by Yoshitaka Saga et al. will be useful for engineering photofunctions in natural light-harvesting proteins and for understanding the alteration from BChl pigments in anoxygenic photosynthetic bacteria to Chl pigments in oxygenic organisms in the evolution of photosynthesis.*

The authors observed their sample in 20 mM Tris buffer containing 150 mM NaCl (pH 8.0) using a  home-built frequency modulation AFM ( FM-AFM ) with NANOSENSORS™ PPP-NCHAuD AFM probes.*

Figure 6 from «Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2” by Y. Saga et al.: FM-AFM images of native LH2 (A) and oxidized LH2 (B) adsorbed on mica taken in 20 mM Tris buffer containing 150 mM NaCl (pH 8.0). Left: wide images. Middle: locally enlarged images of single LH2 proteins. Right: overlapped height-profiles of ten proteins. NANOSENSORS PPP-NCHAuD AFM probes were used.
Figure 6 from «Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2” by Y. Saga et al.: FM-AFM images of native LH2 (A) and oxidized LH2 (B) adsorbed on mica taken in 20 mM Tris buffer containing 150 mM NaCl (pH 8.0). Left: wide images. Middle: locally enlarged images of single LH2 proteins. Right: overlapped height-profiles of ten proteins.

*Yoshitaka Saga, Kiyoshiro Kawano, Yuji Otsuka, Michie Imanishi, Yukihiro Kimura, Sayaka Matsui & Hitoshi Asakawa
Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2
Nature, Scientific Reports, volume 9, Article number: 3636 (2019)
DOI: https://doi.org/10.1038/s41598-019-40082-y

Please follow this external link to read the full article: https://www.nature.com/articles/s41598-019-40082-y

Open Access The article “Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2” by Yoshitaka Saga, Kiyoshiro Kawano, Yuji Otsuka, Michie Imanishi, Yukihiro Kimura, Sayaka Matsui & Hitoshi Asakawa is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Nanoscale chemical imaging by photoinduced force microscopy

NANOSENSORS PPP-NCHAu and PPP-FMAu AFM tips were used in the research for this interesting paper

Derek Novak et al.
Nanoscale chemical imaging by photoinduced force microscopy
Science Advances 
25 Mar 2016
Vol. 2, no. 3, e1501571
DOI: 10.1126/sciadv.1501571
This work is licensed under CC BY-NC (http://creativecommons.org/licenses/by-nc/4.0)

Abstract
Correlating spatial chemical information with the morphology of closely packed nanostructures remains a challenge for the scientific community. For example, supramolecular self-assembly, which provides a powerful and low-cost way to create nanoscale patterns and engineered nanostructures, is not easily interrogated in real space via existing nondestructive techniques based on optics or electrons. A novel scanning probe technique called infrared photoinduced force microscopy (IR PiFM) directly measures the photoinduced polarizability of the sample in the near field by detecting the time-integrated force between the tip and the sample. By imaging at multiple IR wavelengths corresponding to absorption peaks of different chemical species, PiFM has demonstrated the ability to spatially map nm-scale patterns of the individual chemical components of two different types of self-assembled block copolymer films. With chemical-specific nanometer-scale imaging, PiFM provides a powerful new analytical method for deepening our understanding of nanomaterials.

Please follow this external link for the full article http://advances.sciencemag.org/content/2/3/e1501571.full

Core-shell star block copolymers with hydrophobic polystyrene (PS) cores and hydrophilic polymethaacrylate arms (shell section) attached to the PS core
Core-shell star block copolymers with hydrophobic polystyrene (PS) cores and hydrophilic polymethaacrylate arms (shell section) attached to the PS core. Images courtesy of Molecular Vista. A NANOSENSORS PPP-NCHAu AFM tip was used for this application. These images are not part of the above mentioned article but a further illustration of the possiblities.