At 77 K, under excitation at 440 nm, two major fluorescence emission peaks were observed in envelope membranes from spinach chloroplasts at 636 and 680 nm. A narrow range of wavelengths around 440 nm and a wider range of wavelengths between 390 and 440 nm, respectively, were responsible for excitation of the 636 and 680 nm fluorescence emissions which, in marked contrast with thylakoid fluoresc...

Article info: Received: 25 June 2014 Accepted: 13 November 2014 ABSTRACT Glutamine synthetase, an important enzyme of nitrogen metabolism, was purified under sporulating conditions (GSala). The effect of ligands on the tryptophan fluorescence of the purified enzyme GSala was investigated. With increasing concentrations of L-glutamine in GSala, a blue shift in emission maximum with an increase i...

Fluorescence, Delayed Fluorescence, Photosystem I The changes in the fluorescence and delayed fluorescence intensity of spinach leaf as affected by temperature were studied. It was observed that the delayed fluorescence showed a maximum at about 45 °C whereas the fluorescence maximum was at about 55 °C. An examination of the emission spectra of delayed fluorescence at different temperatures sho...

the interactions of β-lactoglobulin ab in the presence of cationic surfactants such as cetyltrimethylammonium bromide and cetyltrimethylammonium p-toluenesulfonate have been investigated using a variety of experimental techniques such as conductivity, uv-vis spectrophotometry and fluorimetry. the conductivity of surfactants aqueous solutions with β-lactoglobulin shows that the cmc of cationic s...

Quercetin (Q) is an important antioxidant with high bioactivity and the potential of being used as SARS-CoV-2 inhibitor. The fluorescence (FL) emission from Q solutions made different polar non-polar solvents (methanol, acetone, chloroform) was measured compared FL powder crystals. In spectra concentration, well in solid state, two features, at 615 nm 670 nm, were observed. As solution concentr...