A novel biosensor for mercuric ions based on motor proteins.
We explored the potential of contractile proteins, actin and myosin, as biosensors of solutions containing mercuric ions. We demonstrate that the reaction of HgCl2 with myosin rapidly inhibits actin-activated myosin ATPase activity. Mercuric ions inhibit the in vitro analog of contraction, namely the ATP-initiated superprecipitation of the reconstituted actomyosin complex. Hg reduces both the rate and extent of this reaction. Direct observation of the propulsive movement of actin filaments (10 nm in diameter and 1 microm long) in a motility assay driven by a proteolytic fragment of myosin (heavy meromyosin or HMM) is also inhibited by mercuric ions. Thus, we have demonstrated the biochemical, biophysical and nanotechnological basis of what may prove to be a useful nano-device.
Martinez-Neira
R
R
Department of Anatomy and Histology, Institute for Biomedical Research, University of Sydney, Anderson Stuart Bldg. F 13, Sydney NSW2006, Australia. robertom@anatomy.usyd.edu.au
Kekic
M
M
Nicolau
D
D
dos Remedios
C G
CG
D015374:Biosensing Techniques / Q000295:instrumentation*; D008628:Mercury / Q000032:analysis* / Q000494:pharmacology; D020409:Molecular Motor Proteins; D009218:Myosins / Q000037:antagonists & inhibitors; D013997:Time Factors
D020409:Molecular Motor Proteins; D009218:Myosins; D008628:Mercury