The inactivation of the Zn+2 metallo enzyme acylamino acid amido hydrolase from Aspergillus oryzae by ethylendiamine-tetraacetate (EDTA) and nitrilotriacetate (NTA) and the effects of Phe and His on this process were studied. Reactivation of the enzyme by Zn+2or Co+2-NTA buffer revealed a dissociation constant for the Zn+2-enzyme of 10~10 M and for the Co+2-enzyme of 10-7-5 m. The kinetic prope...

We have devised an artificial sampling approach generating "absorption flattening" (AF) on the UV-Vis spectrum of a solution of a chiral compound: Tris (ethylendiamine)cobalt(III) chloride (Lambda-Co(en)(3)Cl(3)). We have observed a concomitant red shift of the CD maxima. Related CD and absorption spectra have been calculated from spectra recorded on diluted homogeneous solutions, thus monitori...

Calmodulin (CaM) antagonists, W-7 and W-5, chlorpromazine and haloperidol, especially W-7 inhibited 125I-bovine TSH binding to human and porcine thyroid receptors dose-dependently in the presence of calcium ion. This inhibitory effect of W-7 was diminished by the addition of ethylenglycol tetraacetic acid (EGTA) or ethylendiamine tetraacetic acid (EDTA). CaM also dose-dependently inhibited the ...

Chelate complexes of 1,2-dimesitoylbenzene radical anion with alkali metal cations exhibit in aprotic solution extremely iarge ESR/ENDOR metal coupling constants. For rationaliza­ tion, structures of both the neutral molecule (H 3C)3H2C6C O C 6H4 C O C 6H2(CH3)3, in which the two carbonyl groups are twisted out of the benzene ring plane by dihedral angles of ± 37°, and a sodium contact ion quad...

In the present work, nickel and zinc sulfides ethylendiamine (N2H4C2H4) complexes were prepared in an autoclave at 180 C for 12 h. Transmission electron microscope (TEM) and X-ray powder diffraction were used to study the morphology of the two samples. The infrared absorption spectra were obtained and discussed in the range (200-4000 cm). New bands appeared at about 238,240 and 297 cm assigned ...