Stable isotope labeling tandem mass spectrometry (SILT) to quantify protein production and clearance rates
Year: 2007
Type: article
Abstract: In all biological systems, protein amount is a function of the rate of production and clearance. The speed of a response to a disturbance in protein homeostasis is determined by turnover rate. Quantifying alterations in protein synthesis and clearance rates is vital to understanding disease pathogenesis (e.g., aging, inflammation). No methods currently exist for quantifying production and clearance rates of low-abundance (femtomole) proteins in vivo. We describe a novel, mass spectrometry-based method for quantitating low-abundance protein synthesis and clearance rates in vitro and in vivo in animals and humans. The utility of this method is demonstrated with amyloid-beta (Abeta), an important low-abundance protein involved in Alzheimer's disease pathogenesis. We used in vivo stable isotope labeling, immunoprecipitation of Abeta from cerebrospinal fluid, and quantitative liquid chromatography electrospray-ionization tandem mass spectrometry (LC-ESI-tandem MS) to quantify human Abeta protein production and clearance rates. The method is sensitive and specific for stable isotope-labeled amino acid incorporation into CNS Abeta (+/-1% accuracy). This in vivo method can be used to identify pathophysiologic changes in protein metabolism and may serve as a biomarker for monitoring disease risk, progression, or response to novel therapeutic agents. The technique is adaptable to other macromolecules, such as carbohydrates or lipids.
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Funders: Eli Lilly and Company, American Academy of Neurology, Deutsches Krebsforschungszentrum, National Institutes of Health, National Institute on Aging, National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Neurological Disorders and Stroke, National Center for Research Resources
Awards: G1565341982, Diabetes Research & Training Center, G2051891711, G246532802, G2609131887, Washington University Center for Translational Neuroscience, G3732380844, MUSCLE AMINO ACID METABOLISM IN AIDS CACHEXIA, A Resource for Biomedical Mass Spectrometry, amyloid-beta metabolism/humans/Alzheimer's Disease, G561739401, Alzheimer's Disease Research Center, G766674393, G87705910, Washington University Nutrition Obesity Research Center, Diabetes Research Center, GENERAL CLINICAL RESEARCH CENTER
OpenAlex ID: W2056125067