Hemoglobin Dallas, an alpha-chain variant with a substitution of lysine for asparagine at position 97(G4), was found to have increased oxygen affinity (p1/2 = 1 mmHg at pH 7.3 and 20 degrees C), diminished cooperativity (n, the Hill coefficient = 1.7) and reduced Bohr effect (about 50%). Addition of allosteric effectors (such as 2,3-diphosphoglycerate, inositol hexakisphosphate and bezafibrate) led to a decrease in oxygen affinity and increase in cooperative energy. Kinetic studies at pH 7.0 and 20 degrees C revealed that (i), the overall rate of oxygen dissociation is 1.4-fold slower than that for HbA and (ii), the carbon monoxide dissociation rate is unaffected. The abnormal properties of this hemoglobin variant can be attributed to a more 'relaxed' T-state.

Download full-text PDF

Source
http://dx.doi.org/10.1016/0925-4439(92)90021-eDOI Listing

Publication Analysis

Top Keywords

oxygen affinity
12
hemoglobin dallas
8
dallas alpha
4
alpha 97g4asn-->lys
4
97g4asn-->lys functional
4
functional characterization
4
characterization high
4
oxygen
4
high oxygen
4
affinity natural
4

Similar Publications

Antibody-drug conjugates (ADCs) are an emerging strategy in cancer therapy, enhancing precision and efficacy by linking targeted antibodies to potent cytotoxic agents. This study introduces a novel ADC that combines ribonuclease A (RNase A) with cetuximab (Cet), an anti-EGFR monoclonal antibody, through a polyethylene glycol (PEG) linker (RN-PEG-Cet), aimed to induce apoptosis in KRAS mutant colorectal cancer (CRC) via a ROS-mediated pathway. RN-PEG-Cet was successfully synthesized and characterized for its physicochemical properties, retaining full enzymatic activity in RNA degradation and high binding affinity to EGFR.

View Article and Find Full Text PDF

Acyl-anchored metal-organic cages with interior cryptand-like recognition sites for selective removal of radioactive strontium(II).

Sci Bull (Beijing)

December 2024

Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. Electronic address:

Tailored design of organic linkers or metal nodes can introduce desirable functionalities into metal-organic cages (MOCs), significantly expanding their potential applications. In this study, we present a viable approach for engineering acyl-type metal nodes to create interior oxygen-rich sites within MOCs, enabling specific recognition of metal ions, including radioactive contaminants, while maintaining the structural integrity of the MOCs. A novel MOC featuring a uranyl-sealed calix[4]resorcinarene (C[4]R)-based multisite cavity, referred to as UOC, is synthesized as a prototype.

View Article and Find Full Text PDF

Multifunctional layer-by-layer smart film with betalains and selenium nanoparticles for intelligent meat freshness monitoring and preservation.

Food Chem

January 2025

Laboratory of Agricultural and Food Biophysics, Institute of Biophysics, College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China; Laboratory of Muscle Biology and Meat Science, National Beef Cattle Improvement Center, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China; Laboratory of Meat Quality Analysis and Products Development, Ningxia Xihaigu Institute of High-end Cattle Industry, Haiyuan, Ningxia 755299, China. Electronic address:

Multifunctional pH-responsive films were fabricated via layer-by-layer deposition of gelatin, chitosan, and carboxymethyl cellulose (CMC), incorporating selenium nanoparticles (SeNPs) and beetroot extract (BTE), to monitor and preserve beef freshness. SeNPs were synthesized and characterized via various techniques. BTE exhibited promising functional properties, and films demonstrated a significant color transition from red to yellow across pH 2-14.

View Article and Find Full Text PDF

Prostate cancer (PCa) has emerged to be the second leading cause of cancer-related deaths in men. Molecular imaging of PCa using targeted radiopharmaceuticals specifically to PCa cells promises accurate staging of primary disease, detection of localized and metastasized tumours, and helps predict the progression of the disease. Glutamate urea heterodimers have been popularly used as high-affinity small molecules in the binding pockets of popular and well-characterized PCa biomarker, prostate specific membrane antigen (PSMA).

View Article and Find Full Text PDF

Abstraction of Hydride from Alkanes and Dihydrogen by the Perfluorotrityl Cation.

Angew Chem Int Ed Engl

January 2025

Texas A&M University, Department of Chemistry, Texas A&M University, 77842, College Station, UNITED STATES OF AMERICA.

Lewis acids play a central role in a large variety of chemical transformations. The reactivity of the strongest Lewis acids is typically studied in the context of affinity towards hard bases, such as fluoride or oxygenous species. Carbocations can be viewed as soft Lewis acids, possessing significant affinity for softer bases, such as hydride.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!