Published April 1984
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High and low spin thermal equilibrium in met-haemoglobin and met-myoglobin
Description
Electron Spin Resonance (ESR) is used in the study of high and low spin states mixture for metmyoglobin (metmb) and methemoglobin (methb). Metmb and methb crystals are in the high spin form and only powdered samples show the spin states equilibrium. The temperature dependence of the ESR intensity shows that the high to low spin state ratio, K-1, is an exponential function of the inverse of temeperature. The K-1 slope depends on the sample cooling rate and on the temperature range of observation. The results are explained based on the temperature dependence of the crystal field intensity in hemoproteins and that it can take different values within a certain width near a critical value, Δc. (Author)
Availability note (English)
MF available from INIS under the Report Number.Abstract (Portuguese)
A ressonancia paramagnetica eletronica (RPE) e utilizada para estudar misturas de estados de spin em metmioglobina (metmb) e methemoglobina (methb). Observa-se que monocristais de metmb e methb sao puramente spin alto, so aparecendo a mistura em amostras policristalinas. O estudo da variacao termica do sinal de RPE mostra que a razao entre as fracoes de moleculas no estado de spin alto em relacao as de spin baixo, K-1, dependente exponencialmente do inverso da temperatura. A taxa de variacao de K-1 depende da velocidade de congelamento da amostra e da regiao de temperatura observada.-Os resultados sao interpretados com base na hipotese de que o campo cristalino das proteinas depende da temperatura e tem uma distribuicao de valores em torno de um valor critico, Δ c. (Autor)Files
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Additional details
Publishing Information
- Imprint Pagination
- 8 p.
- Report number
- PUC-TN--10/84
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 18074828
- Subject category
- S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
- Descriptors DEI
- CRYSTAL FIELD; CRYSTALS; ELECTRON SPIN RESONANCE; HEMOGLOBIN; HIGH SPIN STATES; SPIN; TEMPERATURE DEPENDENCE; ULTRALOW TEMPERATURE; VERY LOW TEMPERATURE
- Descriptors DEC
- ANGULAR MOMENTUM; CARBOXYLIC ACIDS; ENERGY LEVELS; GLOBINS; HETEROCYCLIC ACIDS; HETEROCYCLIC COMPOUNDS; MAGNETIC RESONANCE; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PARTICLE PROPERTIES; PIGMENTS; PORPHYRINS; PROTEINS; RESONANCE