User:Andy Maloney/Kinesin & Microtubule Page/Microtubule papers/Tubulin assembly in the presence of calcium ions and taxol microtubule bundling and formation of macrotubule-ring complexes
These are my notes. Please read the article before reading my notes.
- This paper describes how calcium influences different assemblies of microtubules when they are polymerized in the presence of calcium.
- They state that protofilaments are about 5 nm in width.
- Ohhh, reference to glycerol changing the hydrate shell of proteins!
- Tubulin from porcine brains.
- Polymerization of tubulin was done in:
- 2.5 mg/mL tubulin
- 20 mM Morpholinethane sulfonic acid
- 80 mM NaCl
- 1 mM EGTA
- 0.5 mM MgCl2
- 0.36 mM GTP
- 10 µM Taxol
- pH 6.4
- Calcium was added either before polymerization or after.
- They did not see odd microtubule structures in the presence of calcium without Taxol.
- When incubated at 0˚C with Taxol and then polymerized with 2-30 mM calcium, bundles occurred. This is reminiscent of funky structures that can arise from Taxol discussed in this paper.
- When incubated with calcium and then polymerized in Taxol, they saw "macrotubules". These macrotubules were sometimes not fully structured, i.e. they had holes or gaps in them.
- There is an awesome picture of a coiled protofilament.
- Calcium prevents both lateral microtubule assembly and longitudinal tubulin-tubulin dimer assembly.