The potential for using serum albumin (SA) as a broadly applicable molecular sensor was explored in an effort to develop a method for rapid analysis of complex metabolite samples. SA is a protein present at high concentration in blood, which transports a diverse set of compounds including fatty acids, hormones, and drugs. The effectiveness of the bovine ortholog (BSA) as a molecular sensor was tested by analyzing the pool of small molecules bound to the protein after a brief incubation with complex fluids of biological origin. As an initial test, three varietals of red wine were readily distinguished. Further analysis using four varietals of white wine also showed clear separation. In a second analysis using urine, animals in hemorrhagic shock were separated from a group of comparably treated controls. A time course analysis showed that recovery from injury could also be followed using the assay. This finding is significant as there currently is no method or biomarker for predicting the onset of shock. Comparison of samples was based on liquid chromatography mass spectrometry (LCMS) analysis of compounds selectively bound by BSA. Analysis of the samples after protein selection revealed a significant reduction in complexity and clear separation of groups by Principle Component Analysis (PCA). These results show the potential for using cargo-carrying proteins as molecular sensors for screening complex samples without the need for prior knowledge of sample composition or concentration and may streamline elucidation of biomarkers.
Bibliographical noteFunding Information:
The authors would like to thank Dr. Philip Sullivan for helpful discussions and critical reading of the manuscript. The Murdock Charitable Trust and NIH 5P20RR02437 of the Cobre program for support of the mass spectrometry facility at MSU, BB receives support from Office of Naval Research grant #N00014-06-01-1016 and the Nation Science Foundation MCB 1022481 .
- Bovine serum albumin
- Hemorrhagic shock
- Metabolic fingerprinting
- Protein sensor