Studies on the interaction of chlorpromazine with haemoglobin.
01 Oct 1990-International Journal of Biological Macromolecules (Elsevier)-Vol. 12, Iss: 5, pp 297-301
TL;DR: The interaction of chlorpromazine (CPZ), a widely used antipsychotic tranquillizer, with the allosteric protein haemoglobin, has been studied by different methods and the possible nature of the binding site of the protein has been discussed on the basis of the information obtained from fluorescence measurements.
About: This article is published in International Journal of Biological Macromolecules.The article was published on 1990-10-01. It has received 12 citations till now. The article focuses on the topics: Cooperativity.
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TL;DR: The affinity of binding of surfactant to Hb increased with increasing temperature, indicating an endothermic and essentially entropy driven process.
14 citations
TL;DR: Novel polymerization data are presented indicating that CPZ decreases the maximum polymerization rate in a dose-dependent manner and assembly inhibition results from the slackening of oligomer formation during the early stages of polymerisation, of filament elongation and of filament annealing.
10 citations
TL;DR: The extent of oxygen release from two heme proteins, haemoglobin and myoglobin, have been studied in the presence of trifluoperazine and chlorpromazine (5–1000 μM).
Abstract: The extent of oxygen release from two heme proteins, haemoglobin and myoglobin have been studied in the presence of trifluoperazine and chlorpromazine (5–1000 μM).
At a molar ratio (drug: protein) of 1.5, the release of oxygen from haemoglobin was 4 and 15% in the presence of chlorpromazine and trifluoperazine respectively, while from myoglobin the corresponding values were 20 and 40%.
The findings were attributed to the greater extent of local conformational change around tryptophan moieties of each of the proteins induced by trifluoperazine.
10 citations
TL;DR: It is demonstrated for the first time that chlorpromazine is likely to inhibit the process of thrombopoiesis persistently in megakaryocytes, as detected by the long-lasting decrease in the membrane capacitance and the irreversible suppression of the Kv1.3-channel currents.
9 citations
Cites background from "Studies on the interaction of chlor..."
...However, in several in vitro studies, including ours [13], single cells sometimes required higher concentrations of this drug, such as 100 μM or up to 1 mM, to effectively elicit its pharmacological properties [12,25,26,37]....
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...The physiological and therapeutic levels of chlorpromazine ranged from 1 to 10 μM in previous in vitro studies [24], although concentrations as high as 1mMwere required for the drug to protect the erythrocytes from hypotonic lysis [25,26]....
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TL;DR: Spectrophotometric study reveals that an interaction occurs between haemoglobin and haematoporphyrin which leads to a conformational change of the protein, which varies in a positive manner with the stoichiometric ratio of haenoglobin/haemoglobin.
Abstract: The effect of haematoporphyrin, a component of some of the widely used anticancer drugs, on the peroxidase activity of haemoglobin has been studied. Haematoporphyrin increases the haemoglobin-catalysed hydrogen peroxide-mediated oxidation of o-dianisidine or NADH. Spectrophotometric study reveals that an interaction occurs between haemoglobin and haematoporphyrin which leads to a conformational change of the protein. The extent of enhanced peroxidase activity as well as conformational change of the protein vary in a positive manner with the stoichiometric ratio of haematoporphyrin/haemoglobin. An increase in the peroxidase activity of haemoglobin was also observed in the presence of superoxide dismutase, which catalysed the removal of superoxide anion generated during autoxidation of haemoglobin. Possible mechanisms underlying the relation between the conformational change of haemoglobin due to its interaction with haematoporphyrin and the enhanced peroxidase activity are discussed.
5 citations
References
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TL;DR: Human erythrocytes are protected or stabilized against hypotonic and mechanical hemolysis in the presence of low concentrations of many phenothiazines, reserpine, and haloperidol and the decrease in osmotic fragility may be explained possibly by an expansion of the cell membrane.
221 citations
TL;DR: The mechanisms by which chlorpromazine photosensitizes damage to membranes, protein and DNA are described and compared to the mechanisms of photosensitization by psoralens, porphyrins, dyes, and other molecules.
123 citations
TL;DR: The photoexcited chlorpromazine reacts with methanol to yield promazine and 2‐methoxypromazine by two different reaction pathways: hydrogen atom abstraction and nucleophilic attack respectively.
Abstract: — The photoexcited chlorpromazine reacts with methanol to yield promazine and 2-methoxypromazine by two different reaction pathways: hydrogen atom abstraction and nucleophilic attack. respectively. When the photoexcitation of chlorpromazine is performed in the presence of protein or nucleic acids, chlorpromazine binds to the biopolymer. This binding is drastically pH-dependent and correlates to the phototoxic effect exhibited in chlorpromazine—photosensitization of E. coli. No photodynamic damage of E. coli attributed to CPZ-sensitization of molecular oxygen could be detected.
61 citations
TL;DR: In xeroderma pigmentosum, an inherited disorder of defective DNA repair, post-UV colony-forming ability of fibroblasts from patients in complementation groups A through F correlates with the patients' neurological status, which is not significantly different from the curves of the group D fibroblast strains from patients with clinical histories similar to that of the Group G patient.
58 citations
TL;DR: Intensities of peaks further upfield than this peak, previously attributed to deoxy-alpha subunits, are difficult to measure directly especially for samples containing inositol hexaphosphate, which appears to increase with temperature.
44 citations