Calcium-binding Protein Purification
Calcium-binding Protein Purification - Related Videos
03:22
Calcium-Dependent Hydrophobic Interaction Chromatography: A Technique to Purify Calcium-Binding Proteins Based on Hydrophobic Interactions
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2025
In this video, we demonstrate the purification of calcium-binding protein from a dialyzed cell lysate through calcium-dependent hydrophobic interaction chromatography. The calcium-binding proteins expose a hydrophobic region upon binding with calcium, facilitating interaction with a hydrophobic group on resin. Later these proteins are eluted using calcium chelator EDTA that reverses the interaction.
10:22
Protein Purification-free Method of Binding Affinity Determination by Microscale Thermophoresis
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Cited by 54 •
2013
Microscale thermophoresis (MST) can be widely used for determination of binding affinity without purification of the target protein from cell lysates. The protocol involves overexpression of the GFP-fused protein, cell lysis in non-denaturing conditions, and detection of MST signal in the presence of varying concentrations of the ligand.
07:51
Pull-down of Calmodulin-binding Proteins
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Cited by 19 •
2012
Calmodulin (CaM) pull-down assay is an effective way to investigate the interaction of CaM with various proteins. This method uses CaM-sepharose beads for efficient and specific analysis of CaM-binding proteins. This provides an important tool to explore CaM signaling in cellular function.
09:43
Identification of Plant Ice-binding Proteins Through Assessment of Ice-recrystallization Inhibition and Isolation Using Ice-affinity Purification
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Cited by 5 •
2017
This paper outlines the identification of ice-binding proteins from freeze-tolerant plants through the assessment of ice-recrystallization inhibition activity and subsequent isolation of native IBPs using ice-affinity purification.
07:17
Purification of Hsp104, a Protein Disaggregase
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Cited by 24 •
2011
Here, we describe a protocol for the purification of highly active Hsp104, a hexameric AAA+ protein from yeast, which couples ATP hydrolysis to protein disaggregation. This scheme exploits a His6-tagged construct for affinity purification from E. coli followed by anion-exchange chromatography, His6-tag removal with TEV protease, and size-exclusion chromatography.
FAQs
Selectivity comes from the target protein’s response to calcium rather than from calcium alone. Calcium binding can trigger a conformational change, altering the protein’s behavior during chromatographic separation or affinity-based enrichment. By controlling calcium availability, researchers can favor retention or recovery of proteins with the desired interaction, increasing sample specificity for later biochemical or structural studies.
Calcium concentration and buffer conditions are central control variables because they determine whether an interaction is sufficiently selective for enrichment. Adjusting these conditions can change which proteins remain associated with the purification strategy and which cellular components are removed. Consistent control improves reproducibility, allowing differences in protein behavior to be interpreted as biological properties rather than uncontrolled purification variation.
Conformational changes provide more than a separation handle: they connect purification behavior with protein function. A protein’s response to calcium may influence its activity, stability, localization, or interactions, so the purified material can support questions about calcium sensing and regulation. Examining these linked properties helps researchers interpret whether calcium binding has functional significance, not merely whether binding occurs.
An effective workflow starts with a cellular protein sample and uses calcium conditions and an appropriate buffer system to promote the desired interaction. Chromatographic separation then distinguishes enriched calcium-binding proteins from other cellular components. Researchers recover the enriched material under the selected conditions and evaluate it in downstream studies, where controlled preparation supports more specific and reproducible results.
Chromatography provides the practical separation stage by exploiting differences in how proteins behave under calcium-controlled conditions. It helps resolve target proteins from the complex mixture of cellular components, while buffer composition and calcium availability help maintain the intended selectivity. This combination is useful when the goal is not simply to collect protein, but to obtain material suitable for reliable biochemical or structural analysis.
Purified calcium-binding proteins can be directed toward several research outcomes. They may support biochemical assays that test activity, structural analysis that examines molecular organization, antibody production, or studies of signaling pathways governed by calcium sensing. Because purification improves sample specificity, results from these applications can be related more confidently to the target protein rather than to unrelated cellular components.