Toxin Crystal Purification
Toxin Crystal Purification - Related Videos
07:08
Efficient Mammalian Cell Expression and Single-step Purification of Extracellular Glycoproteins for Crystallization
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Cited by 5 •
2015
This is a quick, cost-efficient protocol for the production of secreted, glycosylated mammalian proteins and subsequent single-step purification with sufficient yields of homogenous protein for X-ray crystallography and other biophysical studies.
12:21
Thermostabilization, Expression, Purification, and Crystallization of the Human Serotonin Transporter Bound to S-citalopram
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Cited by 15 •
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This manuscript describes how to screen for thermostabilizing mutations, purify the human serotonin transporter, generate high affinity antibodies, and crystallize the serotonin transporter-antibody complex bound to the antidepressant drug S-citalopram. This protocol can be adapted to the study of other challenging membrane transporters, receptors, and channels.
07:39
Protein Crystallization
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2023
Protein crystallization, obtaining a solid lattice of biomolecules, elucidates protein structure and enables the study of protein function. Crystallization involves drying purified protein under a combination of many factors, including pH, temperature, ionic strength, and protein concentration. Once crystals are obtained, the protein structure can be elucidated by x-ray diffraction and computation of an electron density model. This video introduces protein crystallization and shows a general...
11:41
Crystallization of Salicylic Acid via Chemical Modification
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2023
Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA Processing of biochemicals involves unit operations such as crystallization, ultracentrifugation, membrane filtration, and preparative chromatography, all of which have in common the need to separate large from small molecules, or solid from liquid. Of these, crystallization is the most important from a tonnage standpoint. For that reason, it is commonly employed in the...
14:29
Visualization of Bacterial Toxin Induced Responses Using Live Cell Fluorescence Microscopy
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Cited by 15 •
2012
Methods for purifying the cholesterol binding toxin streptolysin O from recombinant E. coli and visualization of toxin binding to live eukaryotic cells are described. Localized delivery of toxin induces rapid and complex changes in targeted cells revealing novel aspects of toxin biology.
FAQs
Supersaturation creates the concentration state needed for toxin molecules to begin organizing into a solid crystal phase. Once nucleation starts, additional toxin molecules can join the developing structure, allowing crystals to grow. This concentration-dependent transition is central to separating the target toxin from material that remains dissolved in the surrounding solution.
Nucleation establishes the first organized toxin structures, while crystal growth builds those structures into recoverable particles. Distinguishing these stages helps explain why concentration is important: insufficient concentration may not support nucleation, whereas successful growth produces material that can be collected. The resulting crystals provide a more consistent toxin preparation for downstream experiments.
Washing removes soluble contaminants that remain around or accompany the collected crystals, including unwanted proteins, nucleic acids, and other impurities. The process must preserve the target toxin while reducing this background material. Cleaner preparations are particularly valuable when researchers need to interpret toxin-specific structural, binding, or activity measurements.
A typical workflow begins by concentrating the toxin-containing material until supersaturation can promote nucleation and crystal growth. Researchers then collect the formed crystals and wash them to reduce accompanying soluble impurities. This sequence yields concentrated crystalline toxin suitable for subsequent characterization, binding studies, activity testing, or investigations of host-pathogen interactions.
Purified crystals provide consistent toxin material across experiments, which can improve reproducibility. Researchers can use the preparation for structural analysis, receptor or antibody binding studies, and activity testing. Because these experiments examine different properties of the same target material, purification helps connect toxin structure and molecular interactions with its biological effects.
In this field, purified toxin crystals help investigators examine how toxins interact with receptors or antibodies, affect activity measurements, and contribute to host-pathogen interactions. They also support studies of protective immune responses by providing a defined toxin preparation. These applications can clarify mechanisms of disease and improve comparisons between experimental results.