Optimization of protocols for detection of de novo protein synthesis in whole blood samples via azide-alkyne cycloaddition

Aberrant protein synthesis and protein expression are a hallmark of many disorders ranging from cancer Aberrant protein synthesis and protein expression are a hallmark of many disorders ranging from cancer to neuropsychiatry. Blood-based biomarkers indicative of changes in proteomes have long been held to be potentially useful with respect to disease prognosis and treatment. However, most effort has been focused on unlabelled plasma proteomics which includes non-myeloid origin proteins and no method of dynamically tagging acute changes in proteomes. Herein we report a method for evaluating de novo protein synthesis in whole blood liquid biopsies. Using a modification of the “bioorthogonal noncanonical amino acid tagging” (BONCAT) protocol, rodent whole blood samples were incubated with L-azidohomoalanine (AHA) to allow incorporation of this selectively reactive non-natural amino acid within nascent polypeptides. Overall, we present a rapid and convenient de novo protein synthesis assay usable with whole blood biopsies that can quantify translational change as well as identity of proteins differentially expressed that may be useful for clinical applications