Characterization of the aluminum and beryllium fluoride species bound to F-actin and microtubules at the site of the gamma-phosphate of the nucleotide.
Aluminum fluoride and beryllium fluoride complexes have previously been shown to bind tightly to F-ADP-actin and GDP-microtubules in competition with Pi and to mimic the XDP-Pi transient state of the polymerization. The structure of the bound complexes is investigated here in further detail. Using a fluoride ion-specific electrode, the number of fluoride atoms per aluminum or beryllium atom in the bound complex could be determined. The results indicate that AIF-4 and either BeF2(OH)-.H2O or BeF3-.H2O are the tightly bound species in both F-actin and microtubules. The dependences of the binding on pF and pH are consistent with this conclusion. The possible geometries of aluminum and beryllium fluorides in the gamma-phosphate subsite of the nucleotide are discussed in correlation with the catalytic mechanism of nucleotide hydrolysis.
Combeau
C
C
Laboratoire d'Enzymologie du Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
Carlier
M F
MF
D000199:Actins / Q000302:isolation & purification*; D000244:Adenosine Diphosphate / Q000302:isolation & purification; D000535:Aluminum; D017607:Aluminum Compounds; D000818:Animals; D001608:Beryllium; D005459:Fluorides; D006150:Guanine Nucleotides; D006153:Guanosine Diphosphate / Q000302:isolation & purification*; D008870:Microtubules / Q000032:analysis*; D009132:Muscles / Q000378:metabolism; D011817:Rabbits
D000199:Actins; D017607:Aluminum Compounds; D006150:Guanine Nucleotides; D006153:Guanosine Diphosphate; C035982:beryllium fluoride; D000244:Adenosine Diphosphate; D000535:Aluminum; D001608:Beryllium; D005459:Fluorides; C032311:aluminum fluoride