alpha-Bungarotoxin (alpha-Bgt) is a potent postsynaptic neurotoxin which blocks neurotransmission by binding very tightly to the acetylcholine-receptor (AcChR) protein. We have previously shown (P. Calvo-Fernandez, and M. Martinez-Carrion (1981) Arch. Biochem. Biophys. 208, 154-159) that alpha-Bgt free in its native solution conformation incorporates 12 methyl groups when reductively methylated using formaldehyde and sodium cyanoborohydride. We now show that when the alpha-Bgt molecule is bound to the AcChR contained in native membranes prepared from Torpedo californica electroplax, the number of accessible methylation sites is significantly reduced. This favors a model of alpha-Bgt-AcChR interaction involving significant numbers of lysyl moieties distributed over a reasonably large surface of the toxin molecule. In addition, this paper presents a novel procedure for the rapid and nondestructive dissociation of the toxin-AcChR membrane complex which takes advantage of the thermal instability of the complex.
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http://dx.doi.org/10.1016/0003-9861(83)90100-5 | DOI Listing |
Best Pract Res Clin Anaesthesiol
March 2024
Division of Cardiovascular and Thoracic Anesthesiology, Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, FL, USA. Electronic address:
The care for lung transplantation patients is a complex, multidisciplinary coordination of physician and non-physician teams throughout the perioperative period. The diversity of etiologies of recipient end-stage lung disease further complicate care, as recipients often present with concomitant end-stage cardiac disease. Recently, the use of extracorporeal membrane oxygenation has become the mechanical circulatory support of choice to provide cardiopulmonary stability throughout the perioperative period.
View Article and Find Full Text PDFBest Pract Res Clin Anaesthesiol
March 2024
From the Department of Anesthesiology, Yale School of Medicine, 333 Cedar Street, P.O. Box 208051, New Haven, CT, 06520-8051, USA. Electronic address:
The utilization of extracorporeal membrane oxygenation (ECMO) in complex thoracic surgery has become more frequent in recent years due to advances in technology, increased availability, and improved outcomes. ECMO has emerged as a vital tool to facilitate thoracic surgery for patients who would have otherwise been deemed unsuitable candidates. It has redefined the boundaries of surgical possibility where conventional methods fall short.
View Article and Find Full Text PDFBest Pract Res Clin Anaesthesiol
September 2024
Department of Anaesthesiology, University Hospitals Leuven (BE), Department of Cardiovascular Sciences, KU Leuven (BE), Herestraat 49, B-3000, Leuven, Belgium.
Critical illness during pregnancy poses significant challenges driven by complex interactions between physiological changes, pre-existing conditions, and healthcare disparities. In high-income countries, increasing maternal age and comorbidities complicate obstetric care by triggering an unprecedented rise in cardiac disease during pregnancy, while infections like influenza and COVID-19 are important causes of maternal adult respiratory distress syndrome. Extracorporeal membrane oxygenation (ECMO) gained prominence as a vital intervention, providing respiratory and/or cardiac support, for varying indications between antenatal and postpartum periods.
View Article and Find Full Text PDFCirc Res
January 2025
Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China (X.H., J.Z., C.X., R.C., P.J., X.J., P.H.).
Background: Cardiac ischemia/reperfusion disrupts plasma membrane integrity and induces various types of programmed cell death. The ESCRT (endosomal sorting complex required for transport) proteins, particularly AAA-ATPase Vps4a (vacuolar protein sorting 4a), play an essential role in the surveillance of membrane integrity. However, the role of ESCRT proteins in the context of cardiac injury remains unclear.
View Article and Find Full Text PDFASAP1 is a multidomain Arf GTPase-activating protein (ArfGAP) that catalyzes GTP hydrolysis on the small GTPase Arf1 and is implicated in cancer progression. The PH domain of ASAP1 enhances its activity greater than 7 orders of magnitude but the underlying mechanisms remain poorly understood. Here, we combined Nuclear Magnetic Resonance (NMR), Molecular Dynamic (MD) simulations and mathematical modeling of functional data to build a comprehensive structural-mechanistic model of the complex of Arf1 and the ASAP1 PH domain on a membrane surface.
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