Interaction of rabbit hemopexin with copro- and uroporphyrins

Interactions of the histidine-rich glycoprotein of serum with metals

“…The excitation wavelength was 280 or 290 nm, and the emission maximum was at 338 nm for the rabbit protein (this work) and at 328 nm for human HRG (Morgan, 1978). For absorption, ligand added to equal volumes of buffer served as reference solutions; with fluorescence, ligand added to ovalbumin was used to correct for screening and inner-filter effects (Morgan et al, 1975), except for mercury which quenches ovalbumin fluorescence (Chen, 1976). Spectral measurements were usually made within minutes of mixing protein with ligand, and no changes after this time were noted.…”

“…Equilibrium dialysis was carried out in Plexiglas chambers of 0.2or 2.0-mL total volume by using treated dialysis tubing as described (Morgan et al, 1975). 65Zn was measured in aliquots taken from each side of the chamber; the bound 65Zn was taken to be the difference between the 65Zn in the presence of protein (bound + free) and 65Zn in the other chamber (free).…”