Expression & Purification of GST-DHFR-His in E. coli

These flashcards cover key terms and concepts from the lecture on the expression and purification of GST-DHFR-His in E. coli, emphasizing enzymatic activity and purification techniques.

Dihydrofolate reductase (DHFR)

An essential enzyme that catalyzes the reduction of dihydrofolate to tetrahydrofolate, playing a critical role in DNA and amino acid synthesis.

Recombinant protein

A protein that is produced from a genetically engineered organism, which in this study is E. coli expressing the GST-DHFR-His fusion protein.

Fusion protein

A protein made from the joining of two or more genes that originally coded for separate proteins, facilitating purification and activity.

IPTG

Isopropyl β-D-1-thiogalactopyranoside, a molecular compound used to induce protein expression in bacterial cells by mimicking lactose.

Nickel affinity chromatography

A method used to purify proteins that contain a His-tag by using nickel ions that bind to the His residues.

SDS-PAGE

Sodium dodecyl sulfate polyacrylamide gel electrophoresis, a technique used to separate proteins based on their molecular weight.

Spectrophotometric assay

A method to measure enzyme activity by monitoring the absorbance of a solution at specific wavelengths, indicative of substrate conversion.

Specific activity

A measure of enzyme activity, expressed as nanomoles of substrate converted per minute per milligram of enzyme.

Enzymatic activity

The rate at which an enzyme catalyzes a reaction, often measured by the change in absorbance in biochemical assays.

Coomassie Blue staining

A dye used in protein electrophoresis that binds to proteins, allowing visualization of bands corresponding to specific proteins.