Abstract
Serum albumin binding to the yeast form of Candida albicans is described. Two populations of binding site are identified using two complementary spectroscopic techniques: an extrinsic fluorescent probe, 3-hexa-decanoyl-7-hydrocoumarin ([HEXCO) added to the C. albicans yeast cell surface that records the electrostatic surface potential and so responds to the surface binding of serum albumin and secondly a light scattering technique that reveals how albumin modulates aggregation of the yeast population. The albumin binding sites are found to possess different binding affinities and relative abundance leading to different total binding capacities. These are characterized as a receptor population with high affinity binding (Kd ~ 17 μM) but relatively low abundance and a separate population with high abundance but much lower affinity (Kd ~ 364 μM). The low-affinity binding sites are shown to be associated with the yeast cell aggregation. These values are found be dependent on the C. albicans strain and the nature of the culture media; some examples of these effects are explored. The possible physiological consequences of the presence of these sites are speculated in terms of evading the host’s immune response, biofilm formation and possible interkingdom signaling processes.
Highlights
The complexity of the mutual interactions of invasive micro-organisms with their host is becoming much more evident with molecular-level characterizations of many inter-kingdom signaling processes
The introduction of human serum albumin (HSA) to a suspension of yeast cells leads to a reduction in the degree of light scattering but the gradient with respect to the yeast concentration remains is linear and so a scattering gradient can still be determined
The mechanisms by which C. albicans may elude a prospective Host’s immune system is clearly of both fundamental and medical importance and the current work offers some insight into potential roles played by serum albumin in mammalian systems (Human)
Summary
The complexity of the mutual interactions of invasive micro-organisms with their host is becoming much more evident with molecular-level characterizations of many inter-kingdom signaling processes. We have a longstanding interest in the physical properties of Candida albicans that relate to cellular interactions and to cell-cell aggregation [7,8,9] As part of these studies and within our broader research program directed at biomolecular interactions we have developed a comprehensive panel of spectroscopic and imaging-based technologies that illuminate molecular interactions with many kinds of biological surfaces using for example, plasmonics [eg 10], optical scattering techniques [eg 7] and fluorescence [eg 11, 12]. These tools can aid identification of the spatial location of the molecular interactions on the surface of living cells and with model membrane surfaces [eg 13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
