Biomod/2013/NanoUANL/1: Difference between revisions
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==Abstract== | ==Abstract== | ||
Title: A model for silver nanoparticle synthesis by enzymatic reduction of silver ions in a protein cage | '''Title: A model for silver nanoparticle synthesis by enzymatic reduction of silver ions in a protein cage''' | ||
Although Ag-NP synthesis has been widely studied, the variables involved, such as substrate intake, enzymatic activity and atomic nucleation of silver, vary on a nanometric scale and within a specific geometry, which is of great interest. Our proposed model for Ag-NP synthesis involves constrained growth inside a modified viral capsid, aided by the enzyme HRP. A simplification of the system as a series of simple, more accessible scenarios is needed for computational analysis. Through the use of a variety of computer programs and algorithms for many-body problems (such as Monte Carlo), we expect to obtain a model to describe this phenomenon with more detail as a basis for future novel applications in the field of material synthesis. | Although Ag-NP synthesis has been widely studied, the variables involved, such as substrate intake, enzymatic activity and atomic nucleation of silver, vary on a nanometric scale and within a specific geometry, which is of great interest. Our proposed model for Ag-NP synthesis involves constrained growth inside a modified viral capsid, aided by the enzyme HRP. A simplification of the system as a series of simple, more accessible scenarios is needed for computational analysis. Through the use of a variety of computer programs and algorithms for many-body problems (such as Monte Carlo), we expect to obtain a model to describe this phenomenon with more detail as a basis for future novel applications in the field of material synthesis. | ||
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===Introduction=== | ===Introduction=== | ||
Revision as of 19:44, 3 October 2013
Abstract
Title: A model for silver nanoparticle synthesis by enzymatic reduction of silver ions in a protein cage
Although Ag-NP synthesis has been widely studied, the variables involved, such as substrate intake, enzymatic activity and atomic nucleation of silver, vary on a nanometric scale and within a specific geometry, which is of great interest. Our proposed model for Ag-NP synthesis involves constrained growth inside a modified viral capsid, aided by the enzyme HRP. A simplification of the system as a series of simple, more accessible scenarios is needed for computational analysis. Through the use of a variety of computer programs and algorithms for many-body problems (such as Monte Carlo), we expect to obtain a model to describe this phenomenon with more detail as a basis for future novel applications in the field of material synthesis.
Introduction
A nanoparticle is an object between 1 and 100 nanometers in size, with unique size-dependant properties, as they are small enough to confine their electrons and produce quantum effects. A major limitation to existing synthesis protocols is the presence of a wide size distribution, restraining its usefulness in certain applications. The use of a viral capsid as a container for synthesis allows us to study the phenomenon in a controlled environment, ensuring a homogeneity in particle formation.
CCMV
Cowpea Chlorotic Mottle Virus, also know as CCMV, is a plant virus that infects Vigna ungulata, known as the cowpea plant. The CCMV capsid consists of 180 identical copies of a 20 kDa protein that self-assembles into a T=3 icosahedral protein cage with a ~280 Å external diameter and a ~180 Å diameter internal cavity.
The assembly of CCMV has been studied both in vivo and in vitro, and is therefore an appropriate system for constrained reactions. It was the first spherical virus to be assembled in vitro from into an infectious form from its purified components.
Properties
A number of its physical properties can be taken advantage of for nanoscale construction. Some of these include a tolerance for high temperatures, pH's and stability in organic solvents. The viral capsid can undergo reversible pH-dependant structural transition that results in the formation of 60 ~20 Å pores that allow access between the interior and exterior. Under low pH (<6.0) and low ionic strength (i= 0.2) conditions, capsomers devoid of RNA self-assemble; while in higher pH (>7) and ionic strength (i> 1) the structure undergoes disassembly.
Mutagenesis of viral capsids is a well-established technique that allows the alteration of viral structure. These modifications can include changing the total charge or the attachment of ligands to the surface via interactions with the amino acids. Viral capsids have been show to allow the addition of small peptides, up to 30 amino acids. Systems for heterologous expression in a variety of organisms such as V. ungulata, E. coli and P. pastoris allow the production of both wild-type and modified virus-like particles (VLP's).
HRP
Horseradish peroxidase is a ~44 kDa glycoprotein from the peroxidase family, that typically catalyze a reaction in which a wide variety of both organic and inorganic compounds are oxidized, similar to:
[math]\displaystyle{ ROOR' + electron donor (2 e-) + 2H+ → ROH + R'OH }[/math]
(Falta cambiar esto por la fórmula de BRENDA)
There has been a great deal of scientific interest in the enzyme because of its commercial uses, primarily as a component of clinical diagnostic kits and for immunostaining. Its main role in these applications is that of a reporter system. Usually conjugated to specific antibodies or streptavidin, enzymatic activity is detected with substrates like TMB or ABTS, producing color. The three-dimensional structure of HRP (isoenzyme C) was published by Gajhede et al (1997).
Applications
The function of a nanoreactor depends on what molecule it contains, and is also greatly affected by single molecule dynamics, different from the ones usually studied. Given that the conditions of the simulation can be changed, different conditions are able to be tested, varying its versatility. This model can be applied beyond material synthesis, being able to perform a variety of multi-step processes such as biofuel production, emulsification, distillation, drug delivery, medical diagnosis and screening.
