Lactose repressor-operator DNA interactions: kinetic analysis by a surface plasmon resonance biosensor.
1993 (English)In: Analytical Biochemistry, ISSN 0003-2697, E-ISSN 1096-0309, Vol. 214, no 1, 245-51 p.Article in journal (Refereed) Published
Lactose repressor binding to operator DNA and subsequent dissociation of the complex was monitored continuously by a biosensor, measuring surface plasmon resonance. In this analysis a synthetic, double-stranded oligonucleotide containing the operator site was immobilized on the sensor surface and repressor protein was passed over the surface. The formation of the repressor-operator complex was specific and could be inhibited by isopropyl-beta-D-thiogalactopyranoside inducer. From the association curve, the apparent kass was determined to be 1.8 x 10(6) M-1 s-1. Dissociation of the complex was, for the first time for the lac repressor, determined as an uncatalyzed reaction and the kdiss was determined to be 3.4 x 10(-4) s-1. As a reference, the repressor-operator interaction was analyzed by electrophoretic mobility shift assay under similar reaction conditions. With this method the equilibrium binding constant was calculated to be 2.4 (+/- 0.2) x 10(8) M-1. The corresponding value calculated from biosensor data was 5.1 x 10(9) M-1.
Place, publisher, year, edition, pages
1993. Vol. 214, no 1, 245-51 p.
Microbiology in the medical area
IdentifiersURN: urn:nbn:se:uu:diva-319221PubMedID: 8250230OAI: oai:DiVA.org:uu-319221DiVA: diva2:1086323