Modelling <i>Staphylococcus aureus</i>–induced septicemia using NMR

Plummer, Regina; Bodkin, Jennifer A.; Yau, Tsz Wai; Power, Daniel; Pantarat, Namfon; Larkin, Timothy J.; Szekely, David; Bubb, William A.; Sorrell, Tania C.; Kuchel, Philip W.

doi:10.1002/mrm.21392

Cited by 4 publications

(7 citation statements)

References 34 publications

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“…Previous studies by Plummer et al (2007) used the saturation transfer experiment to measure the effects of a-haemolysin (membrane pore former) on the rate of anion exchange via the new pores in human RBCs. The saturation transfer experiment is a form of magnetization transfer analysis that relies on the fact that nuclear spins will remain in a given quantum state for a period of the order of their longitudinal relaxation time, T 1 .…”

Section: Introductionmentioning

confidence: 99%

“…NMR spectroscopy provides a non-invasive means of monitoring biochemical reactions, cell shape changes and membrane transport processes, both fast and slow (Plummer et al, 2007;Pages et al, 2008). DMMP (dimethyl methylphosphonate) and HPA (hypophosphite) exhibit separate intra-and extra-cellular 31 P NMR resonances in the presence of whole RBCs (Kirk and Kuchel, 1986;Kirk et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

“…The overall reduction in peak area carries information on the rate of exchange; the faster the exchange the greater will be the suppression of the area of peak B. Previous studies by Plummer et al (2007) used the saturation transfer experiment to measure the effects of a-haemolysin (membrane pore former) on the rate of anion exchange via the new pores in human RBCs. More extensive explanations of various magnetization transfer experiments are given in Kuchel (1990).…”

Section: Introductionmentioning

confidence: 99%

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Cytoskeletal rearrangements in human red blood cells induced by snake venoms: light microscopy of shapes and NMR studies of membrane function

Yau¹,

Kuchel²,

Koh³

et al. 2012

Cell Biology International

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RBCs (red blood cells) circulating through narrow blood capillaries withstand major deformation. The mechanical and chemical stresses commonly exerted on RBCs continue to attract interest for the study of membrane structure and function. Snake venoms are lethal biochemical 'cocktails' that often contain haemotoxins, metalloproteinases, myotoxins, neurotoxins, phosphodiesterases, phospholipases and proteases. We have monitored the effects of 4 snake venoms (Pseudechis guttatus, Oxyuranus scutellatus, Notechis scutatus and Naja kaouthia) on human RBCs using NMR spectroscopy, DIC (differential interference contrast) and confocal light microscopy. RBCs underwent reproducible stomatocytosis, with unusual geographical-like indentations, spherocytosis, followed by rapid lysis. Confocal micrographs using a fluorescent dye linked to phalloidin showed that the change in morphology was associated with the aggregation of actin in the cytoskeleton. (31)P NMR saturation transfer experiments recorded transport of the univalent anion HPA (hypophosphite) on a subsecond time scale, thereby reporting on the function of capnophorin or Band 3 linked to the cytoskeleton; anion-exchange activity was substantially reduced by venom treatment. We propose a molecular-cytological hypothesis for the shape and functional changes that is different from, or supplementary to, the more 'traditional' bilayer-couple hypothesis more often used to account for similar morphological changes invoked by other reagents.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cytoskeletal rearrangements in human red blood cells induced by snake venoms: light microscopy of shapes and NMR studies of membrane function

Yau¹,

Kuchel²,

Koh³

et al. 2012

Cell Biology International

View full text Add to dashboard Cite

show abstract

“…experiments [79]. The spectra indicated swelling of RBCs followed by lysis, manifested as an initial decrease in peak-separation, followed by collapse of the two peaks into a singlet as the bacteria lysed the RBCs with their enzymic armoury [79].…”

Section: F Nmrmentioning

confidence: 99%

The NMR ‘split peak effect’ in cell suspensions: Historical perspective, explanation and applications

Kuchel

Kirk

Shishmarev

2018

Progress in Nuclear Magnetic Resonance Spectroscopy

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The physicochemical environment inside cells is distinctly different from that immediately outside. The selective exchange of ions, water and other molecules across the cell membrane, mediated by integral, membrane-embedded proteins is a hallmark of living systems. There are various methodologies available to measure the selectivity and rates (kinetics) of such exchange processes, including several that take advantage of the non-invasive nature of NMR spectroscopy. A number of solutes, including particular inorganic ions, show distinctive NMR behaviour, in which separate resonances arise from the intra- and extracellular solute populations, without the addition of shift reagents, differences in pH, or selective binding partners. This 'split peak effect/phenomenon', discovered in 1984, has become a valuable tool, used in many NMR studies of cellular behaviour and function. The explanation for the phenomenon, based on the differential hydrogen bonding of the reporter solutes to water, and the various ways in which this phenomenon has been used to investigate aspects of cellular biochemistry and physiology, are the topics of this review.

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“…However, there is evidence that pore formation by α -hemolysin ( α -toxin, AFT) contributes to the pathogenesis of sepsis [90]. As an example, erythrocyte lysis by AFT could be directly imaged [91]. Downregulation of AFT expression in vivo clearly reduces virulence of S. aureus [92, 93].…”

Section: α-Hemolysin γ-Hemolysin and Leukocidins From Staphylocomentioning

confidence: 99%

Role of Pore-Forming Toxins in Neonatal Sepsis

Sonnen

Henneke

2013

Clinical and Developmental Immunology

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Protein toxins are important virulence factors contributing to neonatal sepsis. The major pathogens of neonatal sepsis, group B Streptococci, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus, secrete toxins of different molecular nature, which are key for defining the disease. Amongst these toxins are pore-forming exotoxins that are expressed as soluble monomers prior to engagement of the target cell membrane with subsequent formation of an aqueous membrane pore. Membrane pore formation is not only a means for immediate lysis of the targeted cell but also a general mechanism that contributes to penetration of epithelial barriers and evasion of the immune system, thus creating survival niches for the pathogens. Pore-forming toxins, however, can also contribute to the induction of inflammation and hence to the manifestation of sepsis. Clearly, pore-forming toxins are not the sole factors that drive sepsis progression, but they often act in concert with other bacterial effectors, especially in the initial stages of neonatal sepsis manifestation.

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Modelling Staphylococcus aureus–induced septicemia using NMR

Cited by 4 publications

References 34 publications

Cytoskeletal rearrangements in human red blood cells induced by snake venoms: light microscopy of shapes and NMR studies of membrane function

Cytoskeletal rearrangements in human red blood cells induced by snake venoms: light microscopy of shapes and NMR studies of membrane function

The NMR ‘split peak effect’ in cell suspensions: Historical perspective, explanation and applications

Role of Pore-Forming Toxins in Neonatal Sepsis

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