Helen Harris

Publications (4)6.32 Total impact

• Article: Functional imaging of microdomains in cell membranes.

  James Duggan, Ghadir Jamal, Mark Tilley, Ben Davis, Graeme McKenzie, Kelly Vere, Michael G Somekh, Paul O'Shea, Helen Harris
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  ABSTRACT: The presence of microdomains or rafts within cell membranes is a topic of intense study and debate. The role of these structures in cell physiology, however, is also not yet fully understood with many outstanding problems. This problem is partly based on the small size of raft structures that presents significant problems to their in vivo study, i.e., within live cell membranes. But the structure and dynamics as well as the factors that control the assembly and disassembly of rafts are also of major interest. In this review we outline some of the problems that the study of rafts in cell membranes present as well as describing some views of what are considered the generalised functions of membrane rafts. We point to the possibility that there may be several different 'types' of membrane raft in cell membranes and consider the factors that affect raft assembly and disassembly, particularly, as some researchers suggest that the lifetimes of rafts in cell membranes may be sub-second. We attempt to review some of the methods that offer the ability to interrogate rafts directly as well as describing factors that appear to affect their functionality. The former include both near-field and far-field optical approaches as well as scanning probe techniques. Some of the advantages and disadvantages of these techniques are outlined. Finally, we describe our own views of raft functionality and properties, particularly, concerning the membrane dipole potential, and describe briefly some of the imaging strategies we have developed for their study.
  European Biophysics Journal 10/2008; 37(8):1279-89. · 2.14 Impact Factor
• Article: Visualizing the solubilization of supported lipid bilayers by an amphiphilic peptide.

  Shellie M Rigby-Singleton, Martyn C Davies, Helen Harris, Paul O'Shea, Stephanie Allen
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  ABSTRACT: The effect of the presequence peptide of cytochrome c oxidase subunit IV (p25) on supported phospholipid bilayers (SPBs) was visualized using atomic force microscopy (AFM). The presequence was found to cause the complete disruption of supported bilayers containing neutral lipids. At relatively low concentrations of presequence, the peptide was found to bind to the membrane, coalescing to form microdomains within the liquid-crystalline bilayer that were located predominantly at bilayer-mica boundaries. Further increases in peptide concentration resulted in the formation of holes within the SPB that were spanned by an interpenetrating network of narrower regions of the bilayer, which, at higher applied peptide concentrations, were observed to disappear through a budding process, ultimately leading to the formation of spherical structures at yet higher peptide concentrations. Within this paper, the impact the presequence has upon the structure and order of the membrane is discussed, as is the potential implication of this apparent solubilization process on the translocation of cytochrome c oxidase into the inner mitochondrial membrane.
  Langmuir 08/2006; 22(14):6273-9. · 4.19 Impact Factor
• Article: Sex-role-mediated achievement behaviours and interpersonal dynamics of fifth-grade coeducational physical education classes /

  Solomons, Helen Harris
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  ABSTRACT: Leaf 246 wanting. Microfiche of typescript. Ann Arbor, Xerox University Microfilms, 1977. Thesis (Ph. D.)--Bryn Mawr College. Bibliography: ℓ. 248-258.
• Article: A validity study of the marital individuation questionnaire /

  Kitchens, Helen Harris
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  ABSTRACT: Abstract. Typescript. Thesis (D. Ed.)--Auburn University, 1990. Vita. Includes bibliographical references (leaves 61-67).