Background: The aim of the present study was application of haemoglobin absorption spectroscopy as a distinguishing tool for identification of two haemoglobin types-HbA and HbS. Material and Methods: Millimolar absorptivities of normal adult haemoglobin (HbA) and sickle cell haemoglobin (HbS) were monitored at pH values of 7.2 and 5.0, within the ultra violet and visible spectral range (250-...

background: the aim of the present study was application of haemoglobin absorption spectroscopy as a distinguishing tool for identification of two haemoglobin types-hba and hbs. material and methods: millimolar absorptivities of normal adult haemoglobin (hba) and sickle cell haemoglobin (hbs) were monitored at ph values of 7.2 and 5.0, within the ultra violet and visible spectral range (250-650...

The role of the protein structural change monitored by absorption band shifts following flash photolysis of CO from myoglobin is discussed in terms of structure-function relationships. Evidence is presented that the Soret band shift does not depend primarily on the covalent linkage of the heme iron to the protein by using the mutation H93G(L) in which the proximal histidine 93 is replaced by gl...

The rebinding kinetics of CO to myoglobin after flash photolysis is nonexponential in time below approximately 180 K; the kinetics is governed by a distribution of enthalpic barriers. This distribution results from inhomogeneities in the protein conformation, referred to as conformational substates. Hole-burning experiments on the Soret and IR CO-stretch bands test the assumption that an inhomo...

A haemoprotein was purified to apparent homogeneity from Bengal-gram seeds. The purified protein exhibited an absorption maximum at 412 nm (Soret band) that upon reduction with dithionite gave rise to a shift in the Soret band to 426 nm with concomitant appearance of an alpha-band at 559 nm and a beta-band at 530 nm. In the reduced state the Bengal-gram haemoprotein showed reactivity towards CO...

It is proposed that xanthophylls, and carotenoids in general, may assist in energy transfer from the chlorophyll Soret band to the Q band. Ground-state (1Ag ) and excited-state (1Bu ) optimizations of violaxanthin (Vx) and zeaxanthin (Zx) are performed in an environment mimicking the light-harvesting complex II (LHCII), including the closest chlorophyll b molecule (Chl). Time-dependent density ...

We have performed gas-phase absorption spectroscopy in the Soret-band region of chlorophyll (Chl) a and b tagged by quaternary ammonium ions together with time-dependent density functional theory (TD-DFT) calculations. This band is the strongest in the visible region of metalloporphyrins and an important reporter on the microenvironment. The cationic charge tags were tetramethylammonium, tetrab...

A sensing method based on resonance localized surface plasmon spectroscopy was developed for low molecular weight substrate and inhibitor molecules binding to heme proteins. Cytochrome P450 proteins have Soret and Q absorption bands in the visible wavelength region. The coupling between the molecular resonance of P450 and the localized surface plasmon resonance (LSPR) of functionalized silver n...

Corroles are a developing class of tetrapyrrole-based molecules with significant chemical potential and relatively unexplored photophysical properties. We combined femtosecond broadband fluorescence up-conversion and fs broadband Vis-pump Vis-probe spectroscopy to comprehensively characterize the photoreaction of 5,10,15-tris-pentafluorophenyl-corrolato-antimony(V)-trans-difluoride (Sb-tpfc-F₂)...

An imidazolium tetrasubstituted cationic porphyrin derivative (the free base and its Zn(II) complex) with five-membered heterocyclic groups in the meso-positions were synthesized using microwave irradiation, and the compounds obtained characterized by (1)H-NMR and mass spectrometry. We observed that under microwave irradiation the yield is similar to when the synthesis is performed under conven...