Catalog Number: 033305
Source: Bovine Brain
Shipping: shipped on dry ice
Storage Conditions: store at -80˚C immediately
Form: clear aqueous solution
Molecular Weight: ~110 kDa
Purity: >99% (SDS-PAGE)
Concentration: 20 mg/ml
Buffer Conditions: 50 mM K-Glutamate and 0.5 mM MgCl2 (pH 7.0)
Labeling Stoichiometry: ~4.0 (check product label)
Shelf Life: check product label for expiration date
Labeled Tubulin-Biotin-XX is generated by reacting Biotin-XX succinimidyl ester with Cycled Tubulin™ (Cat. No. 032005), thereby covalently linking the biomolecule to random tubulin surface lysines. Cycled Tubulin™ is >99% pure and polymerization competent. These properties are maintained during the labeling process by reacting Cycled Tubulin™ with the reactive biotin in its polymerized form and subjecting it to a final polymerization/depolymerization cycle. The final product demonstrates an affinity toward streptavidin-coated beads (Figure 1) and streptavidin-coated coverslips (Figure 2). Specific labeling stoichiometries are indicated on the product label. The product is cryopreserved at 20 mg/ml in 50 mM K-Glutamate and 0.5 mM MgCl2 (pH=7.0).
Activity and Applications
Labeled Tubulin-Biotin-XX will polymerize into microtubules when supplemented with GTP, warmed to 37˚C, and kept above its critical concentration. Polymerization activity is detectable in a variety of experimental systems including fluorescence microscopy assays, turbidity assays, and GTPase assays. Biotinylated tubulin is suitable for use in a variety of experimental applications, and can be combined with other labeled or unlabeled tubulin in generating microtubules in vitro. Cycled Tubulin™ (Cat. No. 032005) is highly recommended as the unlabeled tubulin source in order to minimize tubulin heterogeneity, as labeled tubulin products are derived directly from Cycled Tubulin™. Visit our protocols page for common microtubule polymerization protocols, including the generation of short, rigid microtubules stabilized by GMPCPP or long, flexible microtubules stabilized by taxol.
- optical traps and molecular tweezers
- single molecule kinesin and dynein motor assays
- tubulin affinity columns
- in vitro nanoscale devices
Get a handle on your microtubules
Labeled Tubulin-Biotin-XX binds to streptavidin-coated beads. Coomassie G250-stained protein gel of unbound and bound fractions of tubulin protein samples incubated with Dynabeads® M-280 Streptavidin (Thermo Fisher 11205D). Cycled Tubulin serves as the non-biotinylated negative control. Labeled Tubulin-Biotin-XX fractionates with the streptavidin-coated beads.
Labeled Tubulin-Biotin-XX binds to streptavidin-coated coverslips. Fluorescent images of microtubules incubated in streptavidin-coated flow cells. Microtubules were polymerized at 2 mg/ml total tubulin protein with Labeled Tubulin-Biotin-XX (Cat. No. 033305), Labeled Tubulin-Alexa Fluor® 647 (064705), and Cycled Tubulin™ (Cat. No. 032005) at a 0.5:1:10 ratio and stabilized with GMPCPP. Images acquired on a widefield fluorescence microscope.