Effect of Surface Charge Distribution on the Adsorption Orientation of Proteins to Lipid Monolayers

Tiemeyer, Sebastian; Paulus, Michael; Tolan, Metin

doi:10.1021/la102616h

Cited by 23 publications

(14 citation statements)

References 22 publications

(28 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When present in remote areas from the interface, they could lead to the formation of non-specific complexes. For example, Tiemeyer et al [269] showed that the surface charge distribution is very important for the orientation of proteins on lipid membranes. Significant effects of charges on k on could be sometimes concomitant with effects on k off , indicating that the association rate might be difficult to modulate in a significant and controlled manner independently of the dissociation rate [266].…”

Section: Structure Prediction Of Macromolecular Complexes: Is the Docmentioning

confidence: 99%

On the binding affinity of macromolecular interactions: daring to ask why proteins interact

Kastritis

Bonvin

2013

J. R. Soc. Interface.

386

355

View full text Add to dashboard Cite

Interactions between proteins are orchestrated in a precise and time-dependent manner, underlying cellular function. The binding affinity, defined as the strength of these interactions, is translated into physico-chemical terms in the dissociation constant (Kd), the latter being an experimental measure that determines whether an interaction will be formed in solution or not. Predicting binding affinity from structural models has been a matter of active research for more than 40 years because of its fundamental role in drug development. However, all available approaches are incapable of predicting the binding affinity of protein–protein complexes from coordinates alone. Here, we examine both theoretical and experimental limitations that complicate the derivation of structure–affinity relationships. Most work so far has concentrated on binary interactions. Systems of increased complexity are far from being understood. The main physico-chemical measure that relates to binding affinity is the buried surface area, but it does not hold for flexible complexes. For the latter, there must be a significant entropic contribution that will have to be approximated in the future. We foresee that any theoretical modelling of these interactions will have to follow an integrative approach considering the biology, chemistry and physics that underlie protein–protein recognition.

show abstract

Section: Structure Prediction Of Macromolecular Complexes: Is the Docmentioning

confidence: 99%

On the binding affinity of macromolecular interactions: daring to ask why proteins interact

Kastritis

Bonvin

2013

J. R. Soc. Interface.

386

355

View full text Add to dashboard Cite

show abstract

“…Figure 2 shows the time dependence of the electron density profile for LSZ injected into a buffer solution at pH 3, 7, or 11.5 (close to the isoelectric point of 11.35) with and without the addition of 2 M NaCl. The gray area in each figure corresponds to the simulated profile taken from ref 30, for which the native LSZ molecule (elliptical in shape with approximate dimensions of 30 Â 30 Â 45 Å 3 ) is oriented with its long axis parallel to the airÀwater interface (side-on). In all conditions, the electron density profiles for the initially adsorbed LSZ are highly distorted as compared to the native configuration of a flatter structure at the interface.…”

Section: Section: Macromolecules Soft Mattermentioning

confidence: 99%

Protein Salting Out Observed at an Air−Water Interface

Yano

Uruga

Tanida

et al. 2011

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

b S Supporting Information P rotein crystallization is typically realized by the addition of a salt or an organic solvent to a supersaturated protein solution to decrease the protein solubility. "Salting out" is a method for separating proteins, in which the hydrated salt ions reduce the number of water molecules available for interaction with the proteins. Protein solubility is a macroscopic property resulting from various molecular interactions, including proteinÀprotein, proteinÀion, ionÀwater, and waterÀprotein interactions, and depends on temperature, pH, ion species, and concentration. At low salt concentrations, a "salting-in" region exists, where favorable interactions occur between the protein surface charges and the salt ions in solution to increase protein solubility, which is sometimes associated with protein unfolding. At higher salt concentrations, the repulsive electrostatic interactions are screened, resulting in protein stabilization, and proteinÀprotein interactions such as hydrophobic interactions and dispersion forces can drive aggregation and precipitation. 1À4 The effect of ion species on the solubility of proteins is classified by the well-known Hofmeister series, defined by the concentration of a particular salt needed to precipitate proteins from whole egg white. 5,6 The series are usually given in terms of the ability of the ions to stabilize the structure of proteins. Although Hofmeister ion effects on protein stability are widely reported in protein research, the mechanism is not entirely clear to date. Most previous research on Hofmeister ion effects on proteinÀprotein interactions has been performed in bulk liquids by varying ion species and concentration. 4,7À11The surface tension, that is, the surface free energy per area, can be regarded as the work in bringing a molecule from the interior of a liquid to the surface and is strongly affected by molecular forces and configurations. 12 When salt ions dissociate in water, the magnitude of the surface tension increment indicates the energy required to separate the ions from the water molecules. The molar surface tension increment of the salt has been known to follow the rank order of the Hofmeister series. 13À15 Several recent experiments and computer simulations 16 looking at interfaces have revealed that the propensity for salt anions to adsorb at an airÀwater interface follows an inverse Hofmeister series, that is, strongly hydrated anions effective in precipitating proteins do not adsorb at the airÀwater interface and vice versa. 17 These results suggest that studying the surface adsorption of proteins in a salt solution could provide valuable insight into the salting out of proteins generally.Proteins adsorb at airÀwater interfaces as surfactants. The effect of salt on protein adsorption under equilibrium conditions has been studied by surface pressure measurements, surfacespecific spectroscopies, and neutron reflectometry. 18À22 The amount of adsorption and the thickness of the interfacial layer are strongly dependent on the ...

show abstract

“…The gray area in each figure corresponds to the profile of the native configuration for which the LSZ molecule is oriented with its long axis parallel to the air−water interface (side-on). 37 In all conditions, the electron density profiles for the initially adsorbed LSZ are highly distorted as compared to the native configuration. This is the result of the interface-induced denaturation occurring at hydrophobic interfaces such as the air−water interface.…”

Section: ■ Experimental Methodsmentioning

confidence: 92%

Hofmeister Anion Effects on Protein Adsorption at an Air–Water Interface

et al. 2016

View full text Add to dashboard Cite

Hofmeister anion effects on adsorption kinetics of the positively charged lysozyme (pH < pI) at an air-water interface were studied by surface tension measurements and time-resolved X-ray reflectometry. In the salt-free solution, the protein adsorption rate increases with decreasing the net positive charge of lysozyme. When salt ions are dissolved in water, the protein adsorption rate drastically increases, and the rate is following an inverse Hoffmeister series (Br(-) > Cl(-) > F(-)). This is the result of the strongly polarized halide anion Br(-) being attracted to the adsorbed protein layer due to strong interaction with local electric field, while weakly polarized anion F(-) having no ability to penetrate the protein layer. In X-ray reflection studies, we observed that the lysozyme molecules initially adsorbed on the air-water interface have a flat unfolded structure as previously reported in the salt-free solution. In contrast, in the concentrated salt solutions, the lysozyme molecules begin to refold during adsorption. This protein refolding as a result of protein-protein rearrangements may be a precursor phenomenon of crystallization. The refolding is most significant for Cl(-), which is a good crystallization agent, whereas it is less observed for the strongly hydrated F(-). It is widely known in the bulk state that kosmotropic anions tend to precipitate proteins but at the same time stabilize proteins against denaturing. On the other hand, at the air-water interface where adsorbed proteins usually unfold, we observed chaotropic anions strongly bound to proteins that reduce electrostatic repulsion between protein molecules, and subsequently they induce protein refolding whereas the kosmotropic anions do not.

show abstract

Effect of Surface Charge Distribution on the Adsorption Orientation of Proteins to Lipid Monolayers

Cited by 23 publications

References 22 publications

On the binding affinity of macromolecular interactions: daring to ask why proteins interact

On the binding affinity of macromolecular interactions: daring to ask why proteins interact

Protein Salting Out Observed at an Air−Water Interface

Hofmeister Anion Effects on Protein Adsorption at an Air–Water Interface

Contact Info

Product

Resources

About