PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 10593494

Cytochrome c unfolding on an anionic surface.

C W Herbold·J H Miller·S C Goheen
View original source ↗Export metadata ↓

Abstract

It is now well accepted that the adsorption of proteins to solid supports sometimes involves surface-mediated unfolding. A detailed understanding of the adsorption and surface-mediated unfolding process is lacking. We selected a well studied protein, horse heart cytochrome c, and a weakly ionic support to examine some of the characteristics of protein adsorption under near-physiological conditions. We used high-performance liquid chromatography (HPLC) to investigate the effect of temperature on surface-mediated unfolding. Samples of cytochrome c were introduced to an anionic support, and a NaCl gradient was used to desorb the protein at different times and temperatures. The profiles and retention times were monitored to examine the adhesive properties of cytochrome c to the anionic support. We found that protein retention increased with time at temperatures as low as 0 degrees C, and a significant loss of cytochrome c occurred between 55 degrees C and 70 degrees C. The loss of recovery of cytochrome c indicates irreversible surface-mediated unfolding. The changes in retention time may indicate more subtle transitions, including reversible surface-mediated unfolding of cytochrome c. These results suggest that perturbations in the structure as well as unfolding of cytochrome c can be detected at a lower temperature on an anionic surface than in solution thereby acting like a catalyst for protein unfolding.

Explore related subjects

AdsorptionAnionsBuffersCationsChromatography, High Pressure LiquidChromatography, Ion ExchangeCytochrome c GroupProtein FoldingSodium ChlorideSolutionsTemperatureTime FactorsJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C W Herbold, J H Miller, S C Goheen. 1999-11-26. Cytochrome c unfolding on an anionic surface.. https://doi.org/10.1016/s0021-9673(99)00975-9

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Three-dimensional porous nano-hydroxyapatite@gelatin composite as efficient adsorbent for uranyl ion removal from low-level radioactive wastewater.

The contamination of water resources by uranyl (UO22+) ions poses significant environmental and health risks, requiring the development of efficient and sustainable remediation strategies. Adsorption-based techniques have emerged as promising approaches in the field of UO22+ removal, but the design of cost-effective, high-capacity, and environmentally friendly adsorbents remains challenging. In this study, a three-dimensional porous nano-hydroxyapatite@gelatin (nHAP@Ge) composite was synthesized through glutaraldehyde cross-linking, combining the structural stability of Ge with the high uranium affinity of nHAP. The optimized nHAP@Ge, with a nHAP:Ge mass ratio of 1:0.5, exhibited exceptional UO22+ removal efficiency (97 %), along with high adsorption capacity (364.03 mg/g). Systematic characterizations using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) methods revealed that the porous structure and surface functional groups (-OH, Ca2+, and PO43-) of the material synergistically contributed to binding UO22+ species. Furthermore, the incorporation of nHAP into the Ge framework resulted in enhanced thermal stability while significantly improving the UO22+ adsorption performance. This work presents a scalable, eco-friendly, and recyclable strategy for the effective treatment of uranium-contaminated water, with potential applications in nuclear wastewater treatment and environmental remediation.

Adsorption↗
PubMed2007

Dual radiolabeling to study protein adsorption competition in relation with hemocompatibility.

Human fibrinogen (Fg) and albumin (HSA) were labeled with (3)H and (14)C, respectively. Dual counting allowed the adsorbed amount of the two proteins to be determined simultaneously. Single adsorption, adsorption of the two proteins in competition, but also exchange (substitution by molecules of the same nature) and displacement (desorption under the action of the other protein) experiments were performed on two model surfaces, glass and polystyrene (PS), as well as on pure polyvinylchloride (PVC-s) and on PVC from blood bag (PVC-b). As expected, the adsorbed amount of a single protein is higher on a hydrophobic compared to a hydrophilic surface. When the two proteins are adsorbed in competition, they are found in equal proportion on glass, while HSA is twice more abundant than Fg on PS and PVC-s and about six times more abundant on PVC-b. This trend is related to an increase of the water contact angle of the substrates. For PVC-b, the contact angle is affected by the presence of aliphatic components exposed at the extreme surface, as determined by angle-resolved X-ray photoelectron spectroscopy. In exchange and displacement experiments, the first adsorbed molecules remain dominating on PS while they can be removed from glass. Given the known importance of HSA and Fg adsorption for the fate of materials placed in contact with blood, the method described in this paper may be used as a first approach to orient the design of surfaces with improved hemocompatibility.

Adsorption↗
PubMed2007

Effective immobilization of subunit protein in mesoporous silica modified with ethanol.

Ethoxylated FSM-type mesoporous silica (folded-sheet mesoporous material) with a pore diameter of 6.2 nm (FSM6.2) remarkably enhances rigidly of the structure in aqueous solutions. The esterified material could be used successfully as an adsorbent to accommodate subunit protein, methemoglobin (Fe(3+)). Furthermore, methemoglobin (Fe(3+)) in the pores of ethoxy-FSM is maintained a peroxidase activity similar to the native, indicating methemoglobin retains its fore subunit structure in the pores of FSM6.2.

Adsorption↗