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Social and Behavioral Sciences Commons

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Life Sciences

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J. A. Aquilina

Selected Works

2012

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Articles 1 - 6 of 6

Full-Text Articles in Social and Behavioral Sciences

Understanding The Α-Crystallin Cell Membrane Conjunction, Shih-Ping Su, Jason D. Mcarthur, Michael G. Friedrich, Roger J. W Truscott, J. A. Aquilina Oct 2012

Understanding The Α-Crystallin Cell Membrane Conjunction, Shih-Ping Su, Jason D. Mcarthur, Michael G. Friedrich, Roger J. W Truscott, J. A. Aquilina

J. A. Aquilina

PURPOSE. It is well established that levels of soluble α-crystallin in the lens cytoplasm fall steadily with age, accompanied by a corresponding increase in the amount of membrane-bound α-crystallin. Less well understood, is the mechanism driving this age-dependent membrane association. The aim of this study was to investigate the role of the membrane and its associated proteins and peptides in the binding of α-crystallin. METHODS. Fibre cell membranes from human and bovine lenses were separated from soluble proteins by centrifugation. Membranes were stripped of associated proteins with successive aqueous, urea and alkaline solutions. Protein constituents of the respective membrane isolates …


Tandem Mass Spectrometry Reveals The Quaternary Organization Of Macromolecular Assemblies, J L Benesch, Andrew Aquilina, Brandon T. Ruotolo, Frank Sobott, C V Robinson Oct 2012

Tandem Mass Spectrometry Reveals The Quaternary Organization Of Macromolecular Assemblies, J L Benesch, Andrew Aquilina, Brandon T. Ruotolo, Frank Sobott, C V Robinson

J. A. Aquilina

The application of mass spectrometry (MS) to the study of progressively larger and more complex macromolecular assemblies is proving increasingly useful for structural biologists. The scope of this approach has recently been widened through the application of a tandem MS procedure. This two-step technique involves the selection of specific assemblies in the gas phase, and inducing their dissociation through collisions with argon atoms. Here we investigate the mechanism of this process and show that dissociation of subunits from a macromolecular assembly follows a sequential pathway, with the partitioning of charge between the dissociation products governed primarily by their relative surface …


The Major Toxin From The Australian Common Brown Snake Is A Hexamer With Unusual Gas-Phase Dissociation Properties, Andrew Aquilina Oct 2012

The Major Toxin From The Australian Common Brown Snake Is A Hexamer With Unusual Gas-Phase Dissociation Properties, Andrew Aquilina

J. A. Aquilina

Asymmetric dissociation of multiply charged proteins assemblies has been frequently reported. This phenomenon, which relies on the dissociation of one or more highly charged monomers, has been shown to provide insights into the structure and organization of large monodisperse and polydisperse assemblies. Here, the process of asymmetric dissociation is investigated using the multi-subunit protein, textilotoxin, which has unusually high structural constraints on its monomers due to multiple disulfide linkages. Initially, it is shown that, contrary to previous reports, textilotoxin is made up of 6, rather than 5 subunits. Furthermore, the hexamer exists as two isoforms, one of which is substantially …


Localization Of Low Molecular Weight Crystallin Peptides In The Aging Human Lens Using A Maldi Mass Spectrometry Imaging Approach, S. P. Su, Jason D. Mcarthur, J. A. Aquilina Jul 2012

Localization Of Low Molecular Weight Crystallin Peptides In The Aging Human Lens Using A Maldi Mass Spectrometry Imaging Approach, S. P. Su, Jason D. Mcarthur, J. A. Aquilina

J. A. Aquilina

Low molecular weight (LMW) peptides, derived from the breakdown of the major eye lens proteins, the crystallins, accumulate in the human lens with age. These LMW peptides are associated with age-related lens opacity and cataract, with some shown to inhibit the chaperone activity of α-crystallin. However, the mechanism(s) giving rise to the production of these peptides, as well as their distribution within the lens, are not well understood. In this study, we have mapped the distribution of these crystallin-derived peptides present in human lenses of different ages using matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). Our data showed that most of …


Defining The Structural Basis Of Human Plasminogen Binding By Streptococcal Surface Enolase, Amanda J. Cork, Slobodan Jergic, Sven Hammerschmidt, Bostjan Kobe, Vijay Pancholi, Justin L.P. Benesch, Carol V, Robinson, Nicholas E. Dixon, J Andrew Aquilina, Mark J. Walker Jul 2012

Defining The Structural Basis Of Human Plasminogen Binding By Streptococcal Surface Enolase, Amanda J. Cork, Slobodan Jergic, Sven Hammerschmidt, Bostjan Kobe, Vijay Pancholi, Justin L.P. Benesch, Carol V, Robinson, Nicholas E. Dixon, J Andrew Aquilina, Mark J. Walker

J. A. Aquilina

The flesh-eating bacterium group A Streptococcus (GAS) binds and activates human plasminogen, promoting invasive disease. Streptococcal surface enolase (SEN), a glycolytic pathway enzyme, is an identified plasminogen receptor of GAS. Here we used mass spectrometry (MS) to confirm that GAS SEN is octameric, thereby validating in silico modeling based on the crystal structure of S. pneumoniae -enolase. Site-directed mutagenesis of surface-located lysine residues (SENK252+255A, SENK304A, SENK334A, SENK344E, SENK435L and SEN434-435) was used to examine their roles in maintaining structural integrity, enzymatic function and plasminogen binding. Structural integrity of the GAS SEN octamer was retained for all mutants except SENK344E, as …


Mimicking Phosphorylation Of Alphab-Crystallin Affects Its Chaperone Activity, Heath W. Ecroyd, Sarah Meehan, J Horwitz, Andrew Aquilina, J L Benesch, C V Robinson, Cait Macphee, John Carver Jul 2012

Mimicking Phosphorylation Of Alphab-Crystallin Affects Its Chaperone Activity, Heath W. Ecroyd, Sarah Meehan, J Horwitz, Andrew Aquilina, J L Benesch, C V Robinson, Cait Macphee, John Carver

J. A. Aquilina

No abstract provided.