Effect of Surface Composition on the Adsorption of Photosystem I onto Alkanethiolate Self-Assembled Monolayers on Gold

Abstract

We have used self-assembled monolayers (SAMs) prepared from omega-terminated alkanethiols on gold to generate model surfaces and examine the effect of surface composition on the adsorption of Photosystem I (PSI), stabilized in aqueous solution by Triton X-100. Triton-stabilized PSI adsorbs to high-energy surfaces prepared from HO- and HO2C-terminated alkanethiols but does not adsorb to low-energy surfaces. The inhibition of PSI adsorption at low-energy surfaces is consistent with the presence of a layer of Triton X-100 that adsorbs atop the hydrophobic SAM and presents a protein-resistant poly(ethylene glycol) (PEG) surface. While the presence of the PEG surface prevents the adsorption of PSI, the displacement of the inhibiting layer of Triton X-100 by dodecanol, a more active surfactant, greatly enhances the adsorption of PSI. This inhibiting effect by Triton X-100 can be extended to other protein systems such as bovine serum albumin.

A Composite Polymer Film with both Superhydrophobicity and Superoleophilicity

“…In order to achieve a superhydrophobic and superoleophilic surface, a special roughness is prerequisite (including microstructure, nanostructure, and micro/nanobinary structure), as the wetting property can be amplified by the roughness. [6][7][8][9][10][11][12][13]17,19,20,27] The porous PU film has a WCA and a OCA around 102 AE 1.28 and 17 AE 9.18 (Figure 1a). The sliding WCA of a porous PU film is larger than 608.…”

“…By increasing the surface roughness, the wetting properties (slight hydrophobicity and strong oleophilicity) can be amplified to superhydrophobicity and superoleophilicity. [17,19,20,27] In order to understand the effect of the surface roughness on the wetting properties, the surface structure should first be investigated. Figure 3 shows the FESEM micrographs of the structure of the composite film.…”

Recent advances in the electrochemistry and spectroelectrochemistry of membrane proteins

“…In the case of PSI, it was established that the orientation of the protein can be controlled by the functional groups present on the electrode surface (Lee et al , 1997 ). Detergent-stabilized PSI does not bind on hydrophobic alcanethiol self-assembled monolayers (SAMs) (Ko et al , 2004 ). On hydroxyl-terminated monolayers, 70 % of the immobilized proteins are oriented with the primary electron donor (P700 cofactor) close to the electrode.…”

Electrochemistry of Mitochondria: A New Way to Understand Their Structure and Function

“…However, study of intact organelle with electrochemical method has not been performed, although the electrochemistry of some critical proteins in them, such as cytochrome c [7], has been reported. Recently, some protein complexes in lipid film, such as Photosystem I [8] and Photosystem II [9] in chloroplast, the Complex I [10] and Complex IV [11] in mitochondria, and a few live cell [12] and bacteria [13] are studied by electrochemical technique. And, a kind of organelle, chloroplast, has been used for the preparation of an electrochemical biosensor [14].…”