Search results for "Carboxyhemoglobin"
showing 5 items of 5 documents
Thermal broadening of the Soret band in heme complexes and in heme-proteins: role of iron dynamics
1994
We report the thermal broadening of the Soret band in heme-CO, heme-OH and protoporphyrin IX in the temperature range 300-20 K. For protoporphyrin IX the temperature dependent Gaussian line broadening follows the behavior predicted by the harmonic approximation in the entire temperature range investigated. In contrast, for heme-CO and heme-OH the harmonic behavior is obeyed only up to about 180 K and an anomalous line broadening increase is observed at higher temperatures. This effect is attributed to the onset of anharmonic motions of the iron atom with respect to the porphyrin plane. Comparison with previously reported analogous data for heme proteins enables us to suggest that the onset …
Conformational substates and dynamic properties of carbonmonoxy hemoglobin.
2003
Heme pocket dynamics of human carbonmonoxy hemoglobin (HbCO) is studied by Fourier transform infrared spectroscopy. The CO stretching band at various temperatures in the interval 300-10 K is analyzed in terms of three taxonomic A substates; however, in HbCO the band attributed to the A(1) taxonomic substate accounts for approximately 90% of the total intensity in the pH range 8.8-4.5. Two different regimes as a function of temperature are observed: below 160 K, the peak frequency and the bandwidth of the A(1) band have constant values whereas, above this temperature, a linear temperature dependence is observed, suggesting the occurrence of transitions between statistical substates within th…
Dynamic properties of some β-chain mutant hemoglobins
1995
The thermal behavior of the Soret band relative to the carbonmonoxy derivatives of some beta-chain mutant hemoglobins is studied in the temperature range 300-10 K and compared to that of wild-type carbonmonoxy hemoglobin. The band profile at various temperatures is modeled as a Voigt function that accounts for homogeneous broadening and for the coupling with high- and low-frequency vibrational modes, while inhomogeneous broadening is taken into account with a gaussian distribution of purely electronic transition frequencies. The various contributions to the over-all bandwidth are singled out with this analysis and their temperature dependence, in turn, gives information on structural and dy…
Structure-dynamics-function relationships in Asian elephant (Elephas maximus) myoglobin. An optical spectroscopy and flash photolysis study on functi…
1993
In this work we report the thermal behavior (10–300 K) of the Soret band lineshape of deoxy and carbonmonoxy derivatives of Asian elephant (Elephas maximus) and horse myoglobins together with their carbon monoxide recombination kinetics after flash photolysis; the results are compared to analogous data relative to sperm whale myoglobin. The Soret band profile is modeled as a Voigt function that accounts for the coupling with high and low frequency vibrational modes, while inhomogeneous broadening is taken into account with suitable distributions of purely electronic transition frequencies. This analysis makes it possible to isolate the various contributions to the overall lineshape that; in…
The determination of haemoglobin as cyanhaemiglobin or as alkaline haematin D-575. Comparison of method-related errors.
1989
In order to compare the accuracy of haemoglobin (Hb) determination methods, the commonly used cyanhaemiglobin (HiCN) method and the recently developed alkaline haematin D-575 (AHD) method (R. Zander, W. Lang & H. U. Wolf (1984) Clin. Chim. Acta 136, 83-93; H. U. Wolf, W. Lang & R. Zander (1984) Clin. Chim. Acta 136, 95-104) were tested with respect to method-related errors such as plasma, cell, and Hb errors. Both methods yield a series of more or less significant errors which generally lead to an overestimation of the Hb concentration in the order of 1%. However, in all three cases of plasma errors, i.e. normal plasma error, plasma error in lipaemic blood, and plasma error in bilirubinaemi…