Single-chain toxin was investigated in vitro and in vivo for limited proteolysis into the fully active two-chain toxin. Plasmin from serum, elastase and gelatinase from leucocytes, as well as clostripain from C. histolyticum cleaved single-chain toxin and increased by that way its ability to inhibit [3H]noradrenaline release in vitro. Cultured mouse brain generated fragments from 125I-single-chain toxin which were cell-associated. Some of them comigrated in electrophoresis with light and heavy chain after mercaptolysis. When injected i.v. into rats, 125I-single-chain-toxin disappeared from the blood with a half-life of about 11 h without signs of nicking. However, after its injection into the triceps surae muscle both single- and two-chain toxin were found in the ipsilateral ventral horn of the spinal cord. Thus single-chain toxin is subjected to limited proteolysis by enzymes involved in tissue damage, by cultured brain tissue, and during or after its retrograde axonal transport to the spinal cord. Limited proteolysis is necessary for the release of the light chain known to mediate the action of toxin on several systems.
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http://dx.doi.org/10.1007/BF00251134 | DOI Listing |
Bio Protoc
January 2025
Department of Structural Interactomics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany.
Neurons communicate through neurotransmission at highly specialized junctions called synapses. Each neuron forms numerous synaptic connections, consisting of presynaptic and postsynaptic terminals. Upon the arrival of an action potential, neurotransmitters are released from the presynaptic site and diffuse across the synaptic cleft to bind specialized receptors at the postsynaptic terminal.
View Article and Find Full Text PDFJ Ethnopharmacol
January 2025
Department of Pharmacology of Chinese Materia Medica, Institution of Chinese Integrative Medicine, Hebei Medical University, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, Hebei Province 050017, China.
Ethnopharmacological Relevance: Cepharanthine (CEP) is an alkaloid extracted from Stephania cephalantha Hayata, a traditional Chinese medicine (TCM) renowned for its heatclearing and dehumidifying properties. For centuries, Stephania cephalantha Hayata has been employed in the treatment of a wide range of diseases, including pain, edema, inflammation, and fever.
Aim Of The Study: Our research aims to investigate the role and mechanism of Cepharanthine in ameliorating uric acid (UA) induced neuroinflammatory responses.
Biochem Biophys Res Commun
January 2025
Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan. Electronic address:
Proteolysis-Targeting Chimeras (PROTAC) are a bifunctional molecule that binds to a protein of interest (POI) and a ubiquitin ligase, thereby inducing the ubiquitination and degradation of POI. Many PROTACs currently utilize a limited number of ubiquitin ligases, such as von Hippel-Lindau (VHL) and Cereblon. Because these ubiquitin ligases are widely expressed in normal tissues, unexpected side effects can occur.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Division of Clinical Pharmacology, Department of Pharmacology, Jichi Medical University, Shimotsuke-shi 329-0498, Tochigi, Japan.
Aflibercept and brolucizumab, two anti-VEGF agents used as intravitreal injections in ophthalmology, differ significantly in molecular weight (aflibercept-115 kDa and brolucizumab-26 kDa). Using aqueous humor samples collected after drug administration, we measured and performed a comparative analysis of pharmacokinetics and half-lives of these drugs in the human eye. Since the quantification of monoclonal antibodies (mAbs) using antigen-antibody reactions, such as ELISA, is influenced by endogenous ligands or anti-drug antibodies, we employed nano-surface and molecular-orientation limited proteolysis (nSMOL), combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS), for accurate measurements.
View Article and Find Full Text PDFNat Methods
January 2025
Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
Inducible protein switches are currently limited for use in tissues and organisms because common inducers cannot be controlled with precision in space and time in optically dense settings. Here, we introduce a protein that can be reversibly toggled with a small change in temperature, a stimulus that is both penetrant and dynamic. This protein, called Melt (Membrane localization using temperature) oligomerizes and translocates to the plasma membrane when temperature is lowered.
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