Product Uses Include
A microtubule associated protein (MAP) fraction has been isolated from porcine brain by temperature induced tubulin polymerization followed by ionic exchange chromatography over a phosphocellulose matrix and salt elution (1, 2). The MAP fraction protein is supplied as a white lyophilized powder
Protein purity is determined by scanning densitometry of Coomassie Blue stained protein on a 12% polyacrylamide gel. MAP2 constitutes 70% of the total protein (see Figure 1).
Figure 1: Microtubule associated protein fraction purity determination. A 10 µg sample of MAPF was separated by electrophoresis in a 12% SDS-PAGE system, and stained with Coomassie Blue.
The biological activity of the MAP fraction is determined by the ability of 0.1 mg/ml MAP fraction to enhance the polymerization rate (Vmax) of purified bovine brain tubulin (Cat. # TL238) in vitro. Stringent quality control ensures that the MAP fraction protein will stimulate tubulin polymerization at least five fold when compared to tubulin polymerization without MAP fraction.
Figure 2: Tubulin polymerization in the presence and absence of microtubule associated protein fraction. Tubulin polymerization reactions were carried out as in BK006 with 5% glycerol containing 2 mg/ml of pure bovine brain tubulin (Cat. # TL238) being polymerized in the presence and absence of 0.1 mg/ml MAP fraction protein.
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Question 1: What proteins comprise the microtubule-associated protein fraction?
Answer 1: The MAPF is comprised of a mixture of MAP1, MAP2 and tau proteins.
Question 2: Has the MAPF product been shown to significantly affect tubulin polymerization?
Answer 2: Yes, the biological activity of the MAPF can be determined by the ability of 0.1 mg/ml MAPF to enhance the polymerization rate (Vmax) of purified porcine brain tubulin in vitro. Stringent quality control ensures that the MAPF proteins will stimulate tubulin polymerization approximately five fold when compared to tubulin polymerization without MAPF proteins.
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