Absorbance spectra of rods and some cones were measured by microspectrophotometry in 22 fish species from the brackish-water of the Baltic Sea, and when applicable, in the same species from the Atlantic Ocean (3 spp.), the Mediterranean Sea (1 sp.), or Finnish fresh-water lakes (9 spp.). The main purpose was to study whether there were differences suggesting spectral adaptation of rod vision to...

Pseudomonas putida and rat liver microsomal cytochromes P-450 form both ferric. and ferrous.NO complexes. The ferric.NO complexes are stable and do not possess ESR spectra in the temperature range 5-300 K which suggests that the unpaired electron of the bound NO is spin-paired with the single unpaired d electron of the hemin iron. The ferrous.NO complex of the bacterial cytochrome is quite stab...

We applied optical spectroscopy, magnetic resonance techniques, and redox titrations to investigate the properties of the primary electron donor P700 in photosystem I (PS I) core complexes from cyanobacteria (Thermosynechococcus elongatus, Spirulina platensis, and Synechocystis sp. PCC 6803), algae (Chlamydomonas reinhardtii CC2696), and higher plants (Spinacia oleracea). Remarkable species-spe...

Data have been obtained for the Pf1 virion that establish its stoichiometry and conformational features of its DNA and its protein. The absorbance spectrum of the dissociated virus under alkaline denaturing conditions is fit exactly by spectra for DNA and protein at a mole ratio of one nucleotide per protein subunit. This result, together with three previous values by independent methods, estab...

Vision has been investigated in many species of birds, but few studies have considered the visual systems of large birds and the particular implications of large eyes and long-life spans on visual system capabilities. To address these issues we investigated the visual system of the whooping crane Grus americana (Gruiformes, Gruidae), which is one of only two North American crane species. It is ...

Three new spectrophotometric procedures for the simultaneous determination of fosinopril and hydrochlorothiazide are described. The first method, derivative-differential spectrophotometry, comprised of measurement of the difference absorptivities derivatized in the first-order (DeltaD(1)) of a tablet extract in 0.1 N NaOH relative to that of an equimolar solution in methanol at wavelengths of 2...

I. A procedure employing mild conditions has been developed for purifying Sprotein (hemoprotein 559, erythrocyte), a protein present in the stromal fraction of human red blood cells. S-protein, solubilized by extracting the stroma of red blood cells with pH 8.2 buffer, was purified by chromatography on DEAE-cellulose and Bio-Gel P-6o. 2. The oxidized and reduced forms of this protein show visib...

A new ascorbate-induced chloroplast absorbance change which has the characteristics of a carotenoid shift is described. The absorbance change was light-dependent at pH 7 but not at pH 5. The difference spectra for the light and dark changes were similar, showing a large absorbance peak at 505 nanometers, smaller peaks near 468 and 437 nanometers, and a sharp valley around 483 nanometers. The ab...

Cefoxitin interferes with determination of urinary 17-hydroxycorticosteroids. The apparent concentration of hormone is increased from three- to 10-fold in samples from patients receiving cefoxitin when the Amberlite XAD-2 "Clini-Skreen" column is used. To determine the mechanism of interference, we reacted aqueous solutions of cefoxitin, cortisol, cortisone, and 11-deoxycortisol with phenylhydr...

The ultraviolet absorbance spectra of pyridine nucleotide coenzymes change in the presence of heme-containing proteins. The positions of each of the two main absorbance peaks of NADH are shifted progressively towards shorter wavelengths in the presence of increasing concentrations of hemoglobin, and the third peak, at 220 nm, disappears altogether. Similar changes are seen in the spectra of NAD...