KEAP1-NRF2 PPI-IN-1

Baculovirus-insect cell expression uses recombinant baculovirus to deliver a target gene into insect cells, where late or very-late viral transcription drives recombinant protein production; the method was classically demonstrated by expression of human β-interferon in baculovirus-infected insect cells. The readout is target protein accumulation, assessed by activity, fluorescence if a fluorescent reporter is used, SDS-PAGE, Western blot, or purified protein yield. The system can express soluble, secreted, membrane-associated, and multiprotein targets, but expression outcome depends on the construct, baculovirus vector, insect cell line, multiplicity of infection, infection cell density, harvest time, and target-specific stability.

Cytotoxicity assays are usually based on the assessment of cell membrane damage, which can also be indirectly detected by measuring cell viability. Detection methods include MTT assay, CKK-8 assay, LDH assay and ATP assay, etc.

The bacterial reverse mutation assay detects point mutations that restore amino-acid prototrophy in auxotrophic Salmonella typhimurium or Escherichia coli tester strains; after exposure to a test article, mutagenic activity is read out as an increased number of revertant colonies on minimal agar compared with the vehicle control. The assay uses tester strains with different mutation targets so that base-substitution and frameshift mutagens can be detected, and testing is performed with and without exogenous mammalian metabolic activation because some chemicals require biotransformation to become mutagenic.