Hemoglobin Fort Gordon, alpha2beta2145 Tyr replaced by Asp (HC2), has been observed in a 20-year-old black male with compensatory erythrocytosis. The variant was readily identified by electrophoresis and chromatography, and comprised about 30% of the red cell hemoglobin. The substitution was identified through analyses of tryptic peptides of various digests of the isolated beta chain. The oxygen affinity of whole blood was increased; two components were observed one of which had a greatly increased affinity for oxygen and a markedly reduced subunit cooperativity. It appears that the Tyr replaced by Asp substitution resembles the Tyr replaced by His substitution in hemoglobin Bethesda (Bunn, H. F. et al. (1972) J. Clin. Invest. 51, 2299-2309; Olson, J. S. and Gibson, G. H. (1972) J Biol. Chem. 247, 3662-3670; Adamson et al. (1972) J. Clin. Invest. 51, 2883-2888) in that both inhibit the quarternary change of the oxy to the deoxy conformation, resulting in greatly altered functional properties. Studies of a few members of the family were negative.
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http://dx.doi.org/10.1016/0005-2795(75)90189-0 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States.
The Blue Light Using FAD (BLUF) photoreceptor utilizes a noncovalently bound FAD to absorb light and trigger the initial ultrafast events in receptor activation. FAD undergoes 1 and 2 electron reduction as an enzyme redox cofactor, and studies on the BLUF photoreceptor PixD revealed the formation of flavin radicals (FAD and FADH) during the photocycle, supporting a general mechanism for BLUF operation that involves PCET from a conserved Tyr to the oxidized FAD. However, no radical intermediates are observed in the closely related BLUF proteins AppA and BlsA, and replacing the conserved Tyr with fluoro-Tyr analogs that increase the acidity of the phenol OH has a minor effect on AppA photoactivation in contrast to PixD where the photocycle is halted at FAD.
View Article and Find Full Text PDFFEBS J
December 2024
The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark.
Carbonic anhydrases (CAs) are ideal catalysts for carbon dioxide sequestration in efforts to alleviate climate change. Here, we report the characterisation of three α-CAs that originate from the thermophilic bacteria Persephonella hydrogeniphila (PhyCA), Persephonella atlantica (PaCA), and Persephonella sp. KM09-Lau-8 (PlauCA) isolated from hydrothermal vents.
View Article and Find Full Text PDFAquac Nutr
May 2024
State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
Fishmeal is an important protein source in aquafeed. However, due to the limited natural resources, fishmeal is in short supply, resulting in a price surge for fishmeal. Here, we reported a kind of Chinese medicine residue, endothelium corneum gigeriae galli residue (ECGGR), as a fishmeal substitute in the diets of .
View Article and Find Full Text PDFPharmaceuticals (Basel)
August 2024
Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
Sirtuin 2 (SIRT2), an NAD+-dependent deacetylase, is crucial for regulating vital physiological processes, including aging, DNA repair, and cell cycle progression. Its abnormal activity is linked to diseases such as Parkinson's disease, cancer, and metabolic disorders, making it a potential target for therapeutic intervention. While small molecule inhibitors have been studied, peptide-based inhibitors offer a promising alternative due to their selectivity and bioavailability.
View Article and Find Full Text PDFJ Hum Nutr Diet
December 2024
Vitaflo International Ltd, Liverpool, UK.
Background: 2-(2-Nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) treatment of alkaptonuria (AKU) leads to increased blood tyrosine levels, causing skin issues and potentially sight-threatening corneal keratopathy. Adherence to dietary management of NTBC-induced tyrosinemia, a low-protein diet with or without protein substitutes, can be difficult for patients. This 28-day interventional study evaluated a low tyrosine casein glycomacropeptide (cGMP) protein substitute (TYR sphere)®, a 20 g protein equivalent, cGMP-based protein substitute, in terms of adherence, palatability, usability, comparison to amino acid (AA)-based protein substitutes, gastrointestinal tolerance and metabolic control in adults with NTBC-induced tyrosinaemia.
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