The recombinant SBgLR binds tubulin and MTs <i>in vitro</i>.

<p>A to D, Immunoblotting assay. Aliquots of 2, 4, 8, and 16 µM of SBgLR, tubulin, and BSA were spotted onto PVDF membranes. The membrane was preincubated with (B) or without (A) 10 µM recombinant SBgLR, and then probed with anti-SBgLR antibody. The membrane was preincubated with (D) or without (C) 10 µM tubulin, and then probed with anti-β-tubulin antibody. E and F, The co-sedimentation assay. E, Coomassie brilliant blue stained gels of the pellets (P) and the supernatant (S) from the co-sedimentation assay. The recombinant SBgLR protein mainly appeared in the supernatant (S) after the centrifugation in the absence of tsMTs and co-precipitated with tsMTs into the pellets (P) when tsMTs was added. BSA (12 µM) was used as a negative control. F, Quantitative analysis of the binding between recombinant SBgLR and tsMTs. The binding of the recombinant SBgLR protein to MTs was saturated at a ratio of ∼0.35 mole recombinant SBgLR per mole tubulin dimer estimated by gel scanning.