Encapsulation of Proteins in Transparent Porous Silicate Glasses Prepared by the Sol-Gel Method

Ellerby, Lisa M.; Nishida, Clinton R.; Nishida, Fumito; Yamanaka, Stacey A.; Dunn, Bruce; Valentine, Joan Selverstone; Zink, Jeffrey I.

doi:10.1126/science.1312257

Cited by 734 publications

(488 citation statements)

References 11 publications

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“…A typical experiment in the presence of BZF is as follows. The silica sol was synthesized from tetramethylorthosilicate (Tokyo Kasei Company, Tokyo, Japan) according to the method of Ellerby et al (33). The sol was mixed with 1.5 volumes of 0.87% (w/v) horse carbonmonoxyhemoglobin (slow component) in 50 mM citrate-ammonium buffer, pH 6.7, with 4 mM BZF under CO atmosphere in a rotating sealed glass tube (1-cm diameter) (21)(22)(23)(24).…”

Section: Methodsmentioning

confidence: 99%

Crystal Structure of Horse Carbonmonoxyhemoglobin-Bezafibrate Complex at 1.55-Å Resolution

Shibayama¹,

Miura²,

Tame³

et al. 2002

Journal of Biological Chemistry

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Bezafibrate, an antilipidemic drug, is known as a potent allosteric effector of hemoglobin. The previously proposed mechanism for the allosteric potency of this drug was that it stabilizes and constrains the T-state of hemoglobin by specifically binding to the large central cavity of the T-state. Here we report a new allosteric binding site of fully liganded R-state hemoglobin for this drug. The high resolution crystal structure of horse carbonmonoxyhemoglobin in complex with bezafibrate reveals that the bezafibrate molecule lies near the surface of the E-helix of each ␣ subunit and the complex maintains the quaternary structure of the R-state. Binding is caused by the close fit of bezafibrate into the binding pocket, which is composed of some hydrophobic residues and the heme edge, suggesting the importance of hydrophobic interactions. Upon binding of bezafibrate, the distance between Fe and the N⑀ 2 of distal His E7(␣58) is shortened by 0.22 Å in the ␣ subunit, whereas no significant structural changes are transmitted to the ␤ subunit. Oxygen equilibrium studies of R-state-locked hemoglobin with bezafibrate in a wet porous sol-gel indicate that bezafibrate selectively lowers the oxygen affinity of one type of subunit within the R-state, consistent with the structural data. These results disclose a new allosteric mechanism of bezafibrate and offer the first demonstration of how the allosteric effector interacts with R-state hemoglobin.

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Section: Methodsmentioning

confidence: 99%

Crystal Structure of Horse Carbonmonoxyhemoglobin-Bezafibrate Complex at 1.55-Å Resolution

Shibayama¹,

Miura²,

Tame³

et al. 2002

Journal of Biological Chemistry

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“…14 Immobilized enzymes are used in bioreactors and biosensors (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Current methods for immobilizing enzymes include adsorption or covalent attachment to a support (2)(3)(4), microencapsulation (5,6), and entrapment within a membrane/film (7,8,(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) or gel (9 The synthetic methods developed are related to our work on polymeric microtubules (21)(22)(23)(24). While such tubules (21)(22)(23)(24)(25)(26)(27...…”

Section: Abstract (Maximum 200 Words)mentioning

confidence: 99%

Synthesis of polymeric microcapsule arrays and their use for enzyme immobilization

Parthasarathy

Martin

1994

Nature

328

198

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“…Two common methods to introduce confinement include using sol-gel silica glass and reverse micelles. [13][14][15] Reverse micelles (RM) have been used to study confinement effects because of their many advantages. RMs are thermodynamically stable, nanometer-scale structures that can be formed spontaneously by many kinds of amphiphilic surfactants, such as Sodium bis(2-ethylhexyl) sulfosuccinates (AOTs).…”

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Simulations of the confinement of ubiquitin in self-assembled reverse micelles

Tian

Garcı́a

2011

The Journal of Chemical Physics

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We describe the effects of confinement on the structure, hydration, and the internal dynamics of ubiquitin encapsulated in reverse micelles (RM). We performed molecular dynamics simulations of the encapsulation of ubiquitin into self-assembled protein/surfactant reverse micelles to study the positioning and interactions of the protein with the RM and found that ubiquitin binds to the RM interface at low salt concentrations. The same hydrophobic patch that is recognized by ubiquitin binding domains in vivo is found to make direct contact with the surfactant head groups, hydrophobic tails, and the iso-octane solvent. The fast backbone N-H relaxation dynamics show that the fluctuations of the protein encapsulated in the RM are reduced when compared to the protein in bulk. This reduction in fluctuations can be explained by the direct interactions of ubiquitin with the surfactant and by the reduced hydration environment within the RM. At high concentrations of excess salt, the protein does not bind strongly to the RM interface and the fast backbone dynamics are similar to that of the protein in bulk. Our simulations demonstrate that the confinement of protein can result in altered protein dynamics due to the interactions between the protein and the surfactant.

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Encapsulation of Proteins in Transparent Porous Silicate Glasses Prepared by the Sol-Gel Method

Cited by 734 publications

References 11 publications

Crystal Structure of Horse Carbonmonoxyhemoglobin-Bezafibrate Complex at 1.55-Å Resolution

Crystal Structure of Horse Carbonmonoxyhemoglobin-Bezafibrate Complex at 1.55-Å Resolution

Synthesis of polymeric microcapsule arrays and their use for enzyme immobilization

Simulations of the confinement of ubiquitin in self-assembled reverse micelles

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