The "alkaline haematin D-575" method for determining haemoglobin, described by Zander et al. [1984) Clin. Chim. Acta 136, 83-93) was tested. Claims that different non-ionic detergents in the reagent result in identical values for the haemoglobin concentration being measured could not be verified. It could also not be verified that a stable end-product with unique spectral characteristics is alw...

Alkaline phosphatase has been implicated in matrix vesicle-mediated calcification. We sought to clarify its role in this process by studying the effect of L-tetramisole, a strong uncompetitive inhibitor of this enzyme, and D-tetramisole, its inactive isomer, on the uptake of 32Pi and 45Ca by matrix vesicle-enriched microsomes obtained from chicken epiphyseal cartilage. Uptake of both 32Pi and 4...

31P NMR spectra of phosphate and phosphonate complexes of Escherichia coli alkaline phosphatase have been obtained by Fourier transform NMR methods. One equivalent of P1i, bound to Zn(II) alkaline phosphatase, pH 8, gives rise to a single 31P resonance 2 ppm downfield from that for Pi, and assignable to the noncovalent complex, E-P. Inorganic phosphate in excess of 1 eq per enzyme dimer gives r...

Alkaline phosphatases have binding sites for Zn and Mg, on which enzyme activity is dependent. In this experiment, we tested for the effects of Mg, Zn, Co and Ca on the enzymatic conversion of synthetic pNPP substrate to nitrophenol by bovine intestinal alkaline phosphatase. Different pNPP concentrations were used to determine the Vmax and Km of the reaction for each cation. Higher enzyme activ...

The appearance of kits for the determination of micro amounts of calcium stimulated our interest in the use of Eriochrome Blue SE for this analysis. A study of spectrophotometric curves indicates that, at pH values above 13.7, calcium will complex and cause a change of dye absorbance while magnesium does not complex with the dye. A differential spectrophotometric technic is described in this pa...

A high resolution crystal structure of Escherichia coli alkaline phosphatase in the presence of vanadate has been refined to 1.9 A resolution. The vanadate ion takes on a trigonal bipyramidal geometry and is covalently bound by the active site serine nucleophile. A coordinated water molecule occupies the axial position opposite the serine nucleophile, whereas the equatorial oxygen atoms of the ...