Pulsed field gradient nmr determination of the temperature dependence of the tracer diffusion coefficient of hemoglobin

We have studied the temperature dependence of the tracer diffusion coefficient of carbonmonoxy hemoglobin A (HbA-CO) by means of pulsed-field gradient nmr (PFG-nmr). Measurements were made over the temperature range from 15 to 35°C for samples having concentrations 7.4 and 16.7 g/dL. No significant deviations were found from the predictions of the Stokes-Einstein relation. Thus, this work does not corroborate the recently proposed conformational change in hemoglobin at 22°C. The advantages of PFG-nmr for the study of hemoglobin are discussed.     

Stereochemistry of 1-(4''-hydroxyphenyl)ethanol produced by hydroxylation of 4-ethylphenol by p-cresol methylhydroxylase.

Enzymic hydroxylation of 4-ethylphenol by (a) Pseudomonas putida and (b) highly purified p-cresol methylhydroxylase gave optically active 1-(4'-hydroxyphenyl)-ethanol. The products were transformed into the phenolic methyl ethers and shown to contain 69.5% and 65.6%, respectively, of the (S)-(-)-isomer. The stereochemistry of the reaction is discussed in terms of three distinct steps occurring at the active site of the enzyme.     

Unraveling the "Model Minority" Stereotype: Listening to Asian American Youth.

Unraveling the "Model Minority" Stereotype: Listening to Asian American Youth. Stacey J. Lee. New York: Teachers College Press, 1996. 143 pp.