Table 2.

In vitro inhibition of wild-type human p60 katanin

Proteins in reactionMolar ratio of wt:mutant p60MT-severing activity *
No katanin0:0-
P loop K-A p60/GST-con800:1-
wt-p60/GST-con801:0+++
wt-p60/GST-con80+P loop K-A p601:1+++
wt-p60/GST-con80+P loop K-A p601:2+
wt-p60/GST-con80+P loop K-A p601:4-
wt-p60/GST-con80+P loop K-A/GST-con801:4-
wt-p60/GST-con80+boiled P loop K-A p601:4+++
wt-p60/GST-con80+ΔN-P loop K-A p601:4+++
Severing reactions contained 0.02 μM polymerized tubulin and 0.1 μM 6his-p60/GST-con80. P loop K-A p60/GST-con80 was added at ratios of 1:1, 1:2 etc to 6his-p60. Total GFP-p60 fluorescence associated with the coverslips was ten times that associated with the microtubules (MT).
  • * Average MT length=15 μm; +++, MT gone; +, MT average length reduced by 2μ m.