Streptavidin-biotin binding in the presence of a polymer spacer. A theoretical description.
Streptavidin-biotin binding in the presence of a polymer spacer. A theoretical description.
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DOI：
10.1021/la901735d
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发表时间：
2009-10-20
期刊：
影响因子：
--
通讯作者：
Szleifer I
中科院分区：
文献类型：
--
作者：
Ren CL;Carvajal D;Shull KR;Szleifer I
The binding of streptavidin to biotin located at the terminal ends of poly(ethylene oxide) tethered to a planar surface is studied using molecular theory. The theoretical model is applied to mimic experiments (Langmuir 2008, 24, 2472) performed using drop-shape analysis to study receptor-ligand binding at the oil/water interface. Our theoretical predictions show very good agreements with the experimental results. Furthermore, the theory enables us to study the thermodynamic and structural behavior of the PEO-biotin+streptavidin layer. The interfacial structure, shown by the volume fraction profiles of bound proteins and polymers, indicates that the proteins form a thick layer supported by stretched polymers, where the distribution of bound proteins is greater than the thickness of the height of one layer of proteins. When the polymer spacer is composed of PEO (3000), a thick layer with multi-layers of proteins is formed, supported by the stretched polymer chains. It was found that thick multi-layers of proteins are formed when long spacers are present or at very high protein surface coverages on short spacers. This shows that the flexibility of the polymer spacer plays an important role in determining the structure of the bound proteins due to their ability to accommodate highly distorted conformations to optimize binding and protein interactions. Protein domains are predicted when the amount of bound proteins is small due to the existence of streptavidin-streptavidin attractive interactions. As the number of proteins is increased, the competition between attractive interactions and steric repulsions determines the stability and structure of the bound layer. The theory predicts that the competition between these two forces leads to a phase separation at higher protein concentrations. The point where this transition happens depends on both spacer length and protein surface coverage and is an important consideration for practical applications of these and other similar systems. If the goal is to maximize protein binding, it is favorable to be above the layer transition, as multiple layers can accommodate greater bound protein densities. On the other hand, if the goal is to use these bound proteins as a linker group to build more complex structures, such as when avidin or streptavidin serves as a linker between two biotinylated polymers or proteins, the optimum is to be below the layer transition such that all bound linker proteins are available for further binding.
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影响因子：
8.6
作者：
Elliott, R;Szleifer, I;Schick, M
通讯作者：
Schick, M
影响因子：
3.4
作者：
ALLEN, TM;BRANDEIS, E;ZALIPSKY, S
通讯作者：
ZALIPSKY, S
DOI：
10.1073/pnas.86.7.2190
发表时间：
1989-04-01
影响因子：
11.1
作者：
HENDRICKSON, WA;PAHLER, A;PHIZACKERLEY, RP
通讯作者：
PHIZACKERLEY, RP
影响因子：
2.1
作者：
AHLERS, M;BLANKENBURG, R;SALESSE, C
通讯作者：
SALESSE, C
影响因子：
3.4
作者：
Fattaccioli, Jacques;Baudry, Jean;Bibette, Jerome
通讯作者：
Bibette, Jerome