Real time analysis of lipoprotein transfer from LolA to LolB by means of surface plasmon resonance

Edited by Peter Brzezinski

Received 10 August 2009; received in revised form 20 August 2009; accepted 20 August 2009. published online 28 August 2009.

Abstract

Lipoproteins of Escherichia coli are sorted to the outer membrane through a pathway composed of five Lol proteins. LolA transports lipoproteins released from the inner membrane by LolCDE to LolB on the outer membrane via the periplasm. Interaction between LolA and LolB was speculated to be strong when LolA binds lipoprotein. However, due to a lack of a sensitive method, the kinetics of this reaction have not been examined in detail. We report here the detection of lipoprotein transfer in real time by means of surface plasmon resonance. The kinetic parameters of lipoprotein transfer were determined with wild-type LolA and a mutant defective in it.

Structured summary

MINT-7259948: mlolB (uniprotkb:P61320) binds (MI:0407) to pal (uniprotkb:P0A912) by surface plasmon resonance (MI:0107)

Abbreviations: octylglucoside, n-octyl-β-d-glucopyranoside, IPTG, isopropyl-1-thio-β-d-galactopyranoside, IM, inner membrane, OM, outer membrane, SPR, surface plasmon resonance, SDS–PAGE, sodium dodecyl sulfate–polyacrylamide gel electrophoresis

Keywords: Surface plasmon resonance, Lipoprotein, Molecular chaperone, LolA, LolB

Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan

Corresponding author. Fax: +81 3 5841 8464.

PII: S0014-5793(09)00659-0

doi:10.1016/j.febslet.2009.08.032

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