The effects of the mutation of the alpha 1 beta 2 contact in Hb Malmö (alpha 2 beta 2 97(FG4)His----Gln) on oxygen-binding properties, ease of dissociation into dimeric hemoglobin and stability were studied. The P50 value of Hb Malmö in the absence of organic phosphates was 1.9 mmHg, in contrast to 8.8 mmHg of Hb A. The n-value of Hb Malmö was 1.6. The overall free energy of interaction of oxygen with Hb Malmö was about 25% that of Hb A. The Adair constant, K1, of Hb Malmö was about 10-times larger than that of Hb A, but the K4 of Hb Malmö was similar to that of Hb A. The liganded form of Hb Malmö was found to dissociate into dimers more readily than Hb A by gel filtration on Sephadex G-100. Dissociation into dimeric hemoglobin was enhanced in dilute solutions. Increased instability during mechanical agitation of diluted samples was greater for Hb Malmö than for Hb A. The denaturation rate constants of tetramers of the oxyform of Hb A and Hb Malmö were about 20-times greater than those of dimers of these hemoglobins. The instability of Hb Malmö depends on a greater alpha 1 beta 2 dissociation constant compared with that of Hb A. These findings allow an examination of the role of the intersubunit contact in determining the functional properties and the stability of the hemoglobin molecule.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0167-4838(84)90216-4 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Efficient Extraction, Chemical Characterization, and Bioactivity of Essential Oil From Pine Needles.
Phytochem Anal
March 2025
Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry and Utilization of Agro-Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.
Introduction: Pine needles are a rich source of bioactive compounds, and there are few reports on the extraction and identification of active substances in various types of pine needles.
Objectives: The objective of this study is to enhance the efficiency and yield of pine needle essential oil extraction by employing an innovative ultrasonic-assisted salt-out hydrodistillation technology. It also aims to establish a correlation between gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-nose) to distinguish essential oils from Cedrus deodara, Pinus thunbergii, Pinus massoniana, and Pinus koraiensis.
Cu-catalyzed photoredox chlorotrifluoromethylation of polysubstituted alkenes and pharmacological evaluation.
Org Biomol Chem
March 2025
Univ Rouen Normandie, INSA Rouen Normandie, Univ Caen Normandie, ENSICAEN, CNRS, Institut CARMeN UMR 6064, F-76000 Rouen, France.
A visible-light-mediated chlorotrifluoromethylation catalyzed by a copper-based photo-redox catalyst of internal alkenes is reported. The reaction proceeds with complete regioselectivity under mild reaction conditions using commercially available FCSOCl as both the trifluoromethyl and chlorine source, leading to the synthesis of added-value chemicals with atom-economy. A vast array of internal alkenes were functionalized in decent to good yields, highlighting a great tolerance to various functional groups.
View Article and Find Full Text PDFStatistical considerations for using tolerance interval to set product specification for normally distributed attribute.
J Biopharm Stat
March 2025
Office of Biostatistics, Center for Drug Evaluation and Research, U.S. Food and Drug Evaluation.
Conventionally, the product quality specification and control chart limits are determined as the mean plus and minus 3 sample standard deviations with the assumption that the quality data is normally distributed. These limits correspond to an interval centered at the mean, covering approximately 97.3% of the population.
View Article and Find Full Text PDFInnate and adaptive immunity are intricately linked to the pathogenesis of ulcerative colitis (UC), with dysregulation of the Treg/Th17 balance and M2/M1 macrophage polarization identified as critical factors. Artesunate (ARS) has previously been shown to alleviate UC by inhibiting endoplasmic reticulum stress (ERS). To further investigate the regulatory effects of ARS on immune dysregulation associated with colitis and the role of ERS in this process, an experimental colitis model was established using dextran sulfate sodium (DSS).
View Article and Find Full Text PDFConstruction of pseudotyped human coronaviruses and detection of pre-existing antibodies in the human population.
Biosaf Health
October 2024
Division of HIV/AIDS and Sex-transmitted Virus Vaccines, Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC), State Key Laboratory of Drug Regulatory Science, Beijing 102629, China.
In order to clarify the pre-exist immunity background of different human coronaviruses (HCoV), this study investigated the positive rate of spike (S) protein antibodies of HCoV, including HCoV- severe acute respiratory syndrome (SARS) -associated coronavirus (SARS-CoV-1), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Middle East respiratory syndrome coronavirus (MERS-CoV), HCoV-229E, HCoV-NL63, HCoV-HKU1 and HCoV-OC43, before and after the Coronavirus Disease 2019 (COVID-19) outbreak. We utilized pseudotyped virus-based neutralization assays (PBNA) or enzyme-linked immunosorbent assays (ELISA) to detect antibody levels against HCoV in serum samples collected in 2009-2010 and 2023. The PBNA results showed that neutralizing antibodies against SARS-CoV-1 and the MERS-CoV were negative.
View Article and Find Full Text PDFWant 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!