A membrane protein based biosensor: Use of a phosphate – H + symporter membrane protein (Pho84) in the sensing of phosphate ions

A label free biosensor for direct detection of inorganic phosphate based on potential-step capacitance measurements has been developed. The high-affinity Pho84 plasma membrane phosphate/proton symporter of Saccharomyces cerevisiae was used as a sensing element. Heterologously expressed and purified...

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Bibliographic Details
Published in:	Biosensors & bioelectronics Vol. 27; no. 1; pp. 58 - 63
Main Authors:	Basheer, Shabana, Samyn, Dieter, Hedström, Martin, Thakur, Munna Singh, Persson, Bengt L., Mattiasson, Bo
Format:	Journal Article
Language:	English
Published:	Kidlington Elsevier B.V 15.09.2011 Elsevier
Subjects:	Biochemistry Biokemi Biological and medical sciences Biosensing Techniques Biosensors Biotechnology capacitance Capacitive biosensor detection limit Electric Capacitance electrodes Engineering and Technology Fundamental and applied biological sciences. Psychology Immobilized Proteins - chemistry Industrial Biotechnology Industriell bioteknik ions Ions - analysis Membrane protein membrane proteins Membrane Proteins - chemistry Methods. Procedures. Technologies NATURAL SCIENCES NATURVETENSKAP Pho84 Phosphate phosphates Phosphates - analysis plasma membrane Proton-Phosphate Symporters - chemistry protons Saccharomyces Saccharomyces cerevisiae Saccharomyces cerevisiae Proteins - chemistry Symporter Teknik Various methods and equipments Capacitive biosensor Symporter Membrane protein Pho84 Phosphate Phosphates Biosensor Membrane Protein
ISSN:	0956-5663, 1873-4235, 1873-4235
Online Access:	Get full text
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Summary:	A label free biosensor for direct detection of inorganic phosphate based on potential-step capacitance measurements has been developed. The high-affinity Pho84 plasma membrane phosphate/proton symporter of Saccharomyces cerevisiae was used as a sensing element. Heterologously expressed and purified Pho84 protein was immobilized on a self-assembled monolayer (SAM) on a capacitance electrode. Changes in capacitance were recorded upon exposure to phosphate compared to the control substance, phosphate analogue methylphosphonate. Hence, even without the explicit use of lipid membranes, the Pho84 membrane protein could retain its capacity of selective substrate binding, with a phosphate detection limit in the range of the apparent in vivo K m . A linear increase in capacitance was monitored in the phosphate concentration range of 5–25 μM. The analytical response of the capacitive biosensor is in agreement with that the transporter undergoes significant conformational changes upon exposure to inorganic phosphate, while exposure to the analogue only causes minor responses.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0956-5663 1873-4235 1873-4235
DOI:	10.1016/j.bios.2011.06.024