Biomaterial Database

Quantification and properties of tubulin polymerization in crude brain extracts and preparations of microtubular and purified tubulin. 1978

I V Sandoval, and P Cuatrecasas

Removal of assembled tubulin by centrifugation, followed by measurement in the supernatant of the residual colchicine binding capacity of the non-polymerized, non-precipitable tubulin, is a sensitive and reliable method of measuring tubulin polymerization. This method can be used in both crude and purified preparations of brain tubulin and allows the molar quantification of the total, polymerized and non-polymerized tubulin species in each sample. Only 40--50% of the total tubulin present in crude adult brain extracts is capable of polymerizing when incubated with GTP. The percentage of tubulin polymerizing with GTP is slightly higher in crude foetal brain extracts than in the adult. Incubation of first polymerization supernatants, containing exclusively the GTP-insensitive tubulin, with guanosine 5'-[alpha, beta-methylene]triphosphate (GuoP[CH2]PP) but not with 2.4 M glycerol results in tubulin polymerization. High concentrations of glycerol (2.4 M) promote the polymerization of tubulin in adult but not in crude foetal brain extracts. Both ATP and adenosine 5'-[alpha, beta-methylene]triphosphate (AdoP[CH2]PP) are effective in promoting the polymerization of GDP-free (90%) microtubular protein. The microtubular protein assembled with GuoP[CH2]PP or AdoP[CH2]PP has the unique character of being resistant to calcium concentrations (2mM), which cause complete depolymerization of the tubulin assembled with GTP or ATP. Phosphocellulose-purified tubulin significantly assembles when incubated with GuoP[CH2]PP or AdoP[CH2]PP at protein concentrations at which GTP or ATP do not promote polymerization. 2 micrometer tubulin is the minimal concentration required for polymerization in both crude and purified preparations of adult rat brain tubulin.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008870	Microtubules	Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.	Microtubule
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D001923	Brain Chemistry	Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.	Chemistry, Brain,Brain Chemistries,Chemistries, Brain
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D003078	Colchicine	A major alkaloid from Colchicum autumnale L. and found also in other Colchicum species. Its primary therapeutic use is in the treatment of gout, but it has been used also in the therapy of familial Mediterranean fever (PERIODIC DISEASE).	Colchicine, (+-)-Isomer,Colchicine, (R)-Isomer
D006023	Glycoproteins	Conjugated protein-carbohydrate compounds including MUCINS; mucoid, and AMYLOID glycoproteins.	C-Glycosylated Proteins,Glycosylated Protein,Glycosylated Proteins,N-Glycosylated Proteins,O-Glycosylated Proteins,Glycoprotein,Neoglycoproteins,Protein, Glycosylated,Proteins, C-Glycosylated,Proteins, Glycosylated,Proteins, N-Glycosylated,Proteins, O-Glycosylated
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014404	Tubulin	A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.	alpha-Tubulin,beta-Tubulin,delta-Tubulin,epsilon-Tubulin,gamma-Tubulin,alpha Tubulin,beta Tubulin,delta Tubulin,epsilon Tubulin,gamma Tubulin