Turning tryptophanase into odor-generating biosensors.
An odor-based sensor system that exploits the metabolic enzyme tryptophanase (TPase) as the key component is reported. This enzyme is able to convert an odorless substrate like S-methyl-L-cysteine or L-tryptophan into the odorous products methyl mercaptan or indole. To make a biosensor, TPase was biotinylated so that it could be coupled with a molecular recognition element, such as an antibody, to develop an ELISA-like assay. This method was used for the detection of an antibody present in nM concentrations by the human nose. TPase can also be combined with the enzyme pyridoxal kinase (PKase) for use in a coupled assay to detect adenosine 5'-triphosphate (ATP). When ATP is present in the low μM concentration range, the coupled enzymatic system generates an odor that is easily detectable by the human nose. Biotinylated TPase can be combined with various biotin-labeled molecular recognition elements, thereby enabling a broad range of applications for this odor-based reporting system.
Department of Chemical Engineering, McMaster University, Hamilton, Ontario, L8S 4L7 (Canada).
Yaqin
Y
Xu
Zhuyuan
Z
Zhang
M Monsur
MM
Ali
Joanna
J
Sauder
Xudong
X
Deng
Karen
K
Giang
Sergio D
SD
Aguirre
Robert
R
Pelton
Yingfu
Y
Li
Carlos D M
CD
Filipe
D000255:Adenosine Triphosphate / Q000032:analysis* / Q000378:metabolism; D015374:Biosensing Techniques; D003836:Deodorants / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D009812:Odorants; D011731:Pyridoxal Kinase / Q000737:chemistry / Q000378:metabolism; D014368:Tryptophanase / Q000737:chemistry / Q000378:metabolism*
D003836:Deodorants; D000255:Adenosine Triphosphate; D011731:Pyridoxal Kinase; D014368:Tryptophanase
biosensors; methyl mercaptan; molecular recognition; olfactory detection; tryptophanase