What amino acids does Coomassie blue bind to?
What amino acids does Coomassie blue bind to?
In acidic conditions, Coomassie dye primarily binds basic amino acids (arginine, lysine and histidine).
What amino acids does Coomassie stain?
The Coomassie stain can interact with a small group of amino acids: arginine, histidine, lysine, phenylalanine, tyrosine, and tryptophan making it a useful stain for fingerprint analysis to identify the biological sex of the fingerprint originator.
How does Coomassie blue bind to proteins?
The Coomassie Brilliant Blue dye which is commonly used in SDS-PAGE, was first described by the German scientist Volker Neuhoff. In the staining reaction, the Coomassie dye binds to proteins through ionic interactions between sulfonic acid groups and positive protein amine groups through Van der Waals attractions.
What does Coomassie Blue detect?
Coomassie blue staining is a quick, simple, and affordable method for detecting proteins on gels. It has a detection limit of ~ 0.1–0.5 μg protein, sensitive enough for most daily needs. Silver staining has greater sensitivity, but involves many more steps and solutions (see Silver Staining of SDS-polyacrylamide Gel).
Which amino acid does the Coomassie dye bind to most strongly?
The anionic blue form of the dye, which binds to protein, most strongly to arginine and lysine residues of proteins and also, to lesser extents, histidine and aromatic residues (tryptophan, tyrosine and phenylalanine).
Why is Coomassie blue blue?
The dye molecules bind to proteins including wool (keratin) to form a protein–dye complex. The formation of the complex stabilises the negatively charged anionic form of the dye producing the blue colour, even under acid conditions when most of the molecules in solution are in the cationic form.
How do you make Coomassie brilliant blue?
Dissolve 0.25 g of Coomassie Brilliant Blue R-250 in 90 ml of methanol:H2O (1:1, v/v) and 10 ml of glacial acetic acid. Filter the solution through a Whatman No. 1 filter to remove any particulate matter. Store at room temperature.
What role does Coomassie Blue play in page?
Coomassie Blue stain is used to stain the protein bands in polyacrylamide gels. The dye binds more tightly to the proteins than the to the gel matrix, however, so the dye can subsequently be removed from only the protein-free parts of the gel using a similar solvent from which the dye is omitted. This is the destain.
How does a Coomassie stain work?
The Coomassie dyes (R-250 and G-250) bind to proteins through ionic interactions between dye sulfonic acid groups and positive protein amine groups as well as through Van der Waals attractions. Solutions of the dye, dark blue black at pH 7, turn a clear tan upon acidification.
Why does Coomassie blue change color?
When proteins bind to Coomassie blue in acid solution their positive charges suppress the protonation and a blue colour results. The binding of the dye to a protein causes a shift in the absorption maximum of the dye from 465 to 595 nm and it is the increase in absorbance at 595 nm that is monitored.
What is Coomassie blue used for?
Coomassie Blue is widely used in visualizing proteins separated by either agarose or acrylamide gel electrophoresis. The more popular is Coomassie R250 (Reddish tinted blue) for electrophoresis (more sensitive: can detect as little as 0.1 µg of protein), and Coomassie G250 (Greenish tinted blue) for protein assay in solutions (because it is more
How do you make Coomassie Brilliant Blue staining solution?
45% Methanol (reagent grade) 10% Glacial acetic acid 45% Water 3g/L Coomassie Brilliant Blue R250 Standard Gel staining Protocol Stain solution preparation: Add 100mL of glacial acetic acid to 450mL ultrapure water. Dissolve the 3g of Coomassie Dye in 450mL methanol. Filter the solution before use
How do you dissolve Coomassie Brilliant Blue G-250?
Dissolve 100 mg Coomassie Brilliant Blue G-250 in 50 ml of 95% ethanol and add 100 ml of 85% phosphoric acid while stirring continuously. When the dye has dissolved dilute to 1 l in water.
What is the colour of protonated Coomassie blue?
The protonated form of Coomassie blue is a pale orange-red colour whereas the unprotonated form (Figure 6) is blue. When proteins bind to Coomassie blue in acid solution their positive charges suppress the protonation and a blue colour results.
