Biomaterial Database

Influence of Mg2+ and inorganic phosphates on the assembly of tubulin depleted of its exchangeable guanine nucleotide. 1991

I Hanssens, and J Baert

Interdisciplinary Research Centre, Katholieke Universiteit Leuven, Kortrijk, Belgium.

After the removal of the exchangeable guanine nucleotides by chromatography on phenyl-Sepharose [Hanssens, I., Baert, J., and Van Cauwelaert, F. (1990) Biochemistry 29, 5160-5165] tubulin polymerizations with GTP, GDP, tripolyphosphate, pyrophosphate or orthophosphate as possible stimulants are compared. It is demonstrated that, besides GTP and pyrophosphate, also tripolyphosphate stimulates the assembly into microtubules at high concentrations (4.65 mM) of Mg2+. The influence of Mg2+ is more pronounced in combination with pyrophosphate and tripolyphosphate than with GTP. The microtubules assembled in combination with Mg2+ and tripolyphosphate or pyrophosphate are short, suggesting that especially the nucleation step of microtubule assembly is favoured.

UI	MeSH Term	Description	Entries
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
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
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D011122	Polyphosphates	Linear polymers in which orthophosphate residues are linked with energy-rich phosphoanhydride bonds. They are found in plants, animals, and microorganisms.	Polyphosphate
D011756	Diphosphates	Inorganic salts of phosphoric acid that contain two phosphate groups.	Diphosphate,Pyrophosphate Analog,Pyrophosphates,Pyrophosphate Analogs,Analog, Pyrophosphate
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
D006150	Guanine Nucleotides		Guanine Nucleotide,Guanosine Phosphates,Nucleotide, Guanine,Nucleotides, Guanine,Phosphates, Guanosine
D006153	Guanosine Diphosphate	A guanine nucleotide containing two phosphate groups esterified to the sugar moiety.	GDP,Guanosine 5'-Diphosphate,Guanosine 5'-Trihydrogen Diphosphate,5'-Diphosphate, Guanosine,5'-Trihydrogen Diphosphate, Guanosine,Diphosphate, Guanosine,Diphosphate, Guanosine 5'-Trihydrogen,Guanosine 5' Diphosphate,Guanosine 5' Trihydrogen Diphosphate
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine