Effect of (2)H and (18)O water isotopes in kinesin-1 gliding assay.

We show for the first time the effects of heavy-hydrogen water ((2)H2O) and heavy-oxygen water (H2 (18)O) on the gliding speed of microtubules on kinesin-1 coated surfaces. Increased fractions of isotopic waters used in the motility solution decreased the gliding speed of microtubules by a maximum of 21% for heavy-hydrogen and 5% for heavy-oxygen water. We also show that gliding microtubule speed returns to its original speed after being treated with heavy-hydrogen water.

Effects of surface passivation on gliding motility assays.

In this study, we report differences in the observed gliding speed of microtubules dependent on the choice of bovine casein used as a surface passivator. We observed differences in both speed and support of microtubules in each of the assays. Whole casein, comprised of α(s1), α(s2), β, and κ casein, supported motility and averaged speeds of 966±7 nm/s.