3β-Indoleacrylic Acid Molecular Biology Reagent

Product No. I2273

CAS RN 1204-06-4
EC 214-872-7
Synonyms: 3-(3-Indolyl)acrylic acid, IAA

Product Description

3β-Indoleacrylic Acid (IAA) is used to induce high levels of expression of recombinant and fusion proteins under the control of the tryptophan (trp) promoter in plasmid expression systems.1 As a tryptophan analog, IAA induces expression of the trp operon by effectively competing with the co-pressor tryptophan to bind the trp repressor protein. Using plasmid systems containing a trp promoter, recombinant proteins have been expressed at up to 50 fold higher levels than wild-type levels under the control of the respective natural promoters.2 Typically, IAA is added to E. coli cultures (OD660 ~ 0.2) at concentrations ranging from 10 µg/ml to 100 µg/ml. These conditions, as well as harvest times, must be optimized for each unique expression system and gene of interest.

Precautions and Disclaimer

This product is for R&D use only, not for drug, household, or other uses. Please consult the Safety Data Sheet for information regarding hazards and safe handling practices. 

Preparation Instructions

Prepare stock solution of 2.5 mg/ml in 95% ethanol.

Storage/Stability

Store stock solution at –20 °C.

Suitability Assay

Overnight cultures of E. coli strain DH5a containing a pATH plasmid vector construct containing the E. coli trpE promoter were grown in M9 medium containing ampicillin and tryptophan. The overnight culture was then diluted 1:10 with fresh M9 medium containing ampicillin, but lacking tryptophan, and grown for 1 hour at 37 °C. 3β-Indoleacrylic acid stock solution was then added to a concentration of 10 µg/ml. After 2-3 additional hours of further incubation at 37 °C, bacterial extracts were prepared and analyzed by SDSPAGE. A band with increased intensity correlated to IAA induction.3

Materials

     

 References

  1. Koerner, T.J., et al., High-expression vectors with multiple cloning sites for construction of trpE-fusion genes: pATH vectors. Methods Enzymol., 194, 477-490 (1991)
  2. Wilson M.L. and Macnab R.M., Co-overproduction and localization of the Escherichia coli motility proteins motA and motB. J. Bacteriol., 172, 3932- 3939 (1990)
  3. Ausubel, F.M. et al. (Eds.) Current Protocols in Molecular Biology, (John Wiley & Sons, NY, 1994), p. 16.5.1-16.5.6

 

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