title: X-ray solution scattering studies on vinblastine-induced polymers of microtubule protein: structural characterisation and effects of temperature.
abstract: We report here on X-ray solution scattering and electron microscopy studies of microtubule protein in the presence of the antimitotic drug, vinblastine. In buffer conditions used for microtubule assembly, vinblastine caused the formation of coil-like structures. The coils appeared to be made up of two protofilaments. Details of the structure and behaviour of coils in solution were obtained from interpretation of their solution scattering patterns. Upon increasing temperature from 4 to 37 degrees C the pitch of the coils increased from 25.92 to 26.96 nm. However, little change was observed in their mean diameters (38.46 and 38.45 nm, respectively). Increasing the temperature also favoured increased formation and/or elongation of the coils. The effect of temperature on the pitch was fully reversible. Vinblastine-induced assembly of pure tubulin also showed the formation of coils. However, these coils appeared to consist of only one protofilament. Their mean diameters (38.35 nm) were similar to those of the coils formed from microtubule protein.
authors.affiliation: Daresbury Laboratory, Warrington, United Kingdom.
authors.forename: J L
authors.initials: JL
authors.lastname: Hodgkinson
authors.forename: T
authors.initials: T
authors.lastname: Hutton
authors.forename: F J
authors.initials: FJ
authors.lastname: Medrano
authors.forename: J
authors.initials: J
authors.lastname: Bordas
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D008868:Microtubule Proteins / Q000187:drug effects* / Q000648:ultrastructure; D009391:Nephelometry and Turbidimetry; D009419:Nerve Tissue Proteins / Q000187:drug effects / Q000648:ultrastructure; D013696:Temperature; D014965:X-Rays
chemical_list: D008868:Microtubule Proteins; D009419:Nerve Tissue Proteins