Enhanced mechanical stability of microtubules polymerized with a slowly hydrolyzable nucleotide analogue.
Atomic force microscopy (AFM) has been used to investigate the local mechanical and structural properties of microtubules polymerized using guanylyl-alpha-beta-methylene diphosphonate (GMPCPP), a slowly hydrolyzable analogue of guanosine triphosphate. Using a combination of AFM imaging and local force spectroscopy, GMPCPP-polymerized microtubules have been qualitatively and quantitatively compared to paclitaxel-stabilized microtubules. GMPCPP-polymerized microtubules qualitatively display a greater resistance to destruction by the AFM probe tip during imaging and during deformation measurements and maintain structural details after indentation. In addition, using force spectroscopy taken during the indentation and collapse of individual microtubules with the AFM probe tip, an effective spring constant of the microtubule wall (kMT) for both types of microtubules was determined. The average kMT of GMPCPP-polymerized microtubules, 0.172 N/m, is more than twice that of paclitaxel-stabilized microtubules. These results complement previously reported measurements of bending experiments on GMPCPP-polymerized and paclitaxel-stabilized microtubules.
Munson
Kathleen M
KM
Mulugeta
Philipose G
PG
Donhauser
Zachary J
ZJ
D000970:Antineoplastic Agents / Q000737:chemistry; D001704:Biopolymers / Q000737:chemistry*; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000737:chemistry; D006868:Hydrolysis; D018625:Microscopy, Atomic Force; D008870:Microtubules / Q000737:chemistry*; D017239:Paclitaxel / Q000737:chemistry
D000970:Antineoplastic Agents; D001704:Biopolymers; C004805:5'-guanylylmethylenebisphosphonate; D006160:Guanosine Triphosphate; D017239:Paclitaxel