Advances in experimental medicine and biology | Year: 2013
Progression from health to disease is accompanied by complex changes in protein expression in both the circulation and affected tissues. Large-scale comparative interrogation of the human proteome can offer insights into disease biology as well as lead to the discovery of new biomarkers for diagnostics, new targets for therapeutics, and can identify patients most likely to benefit from treatment. Although genomic studies provide an increasingly sharper understanding of basic biological and pathobiological processes, they ultimately only offer a prediction of relative disease risk, whereas proteins offer an immediate assessment of "real-time" health and disease status. We have recently developed a new proteomic technology, based on modified aptamers, for biomarker discovery that is capable of simultaneously measuring more than a thousand proteins from small volumes of biological samples such as plasma, tissues, or cells. Our technology is enabled by SOMAmers (Slow Off-rate Modified Aptamers), a new class of protein binding reagents that contain chemically modified nucleotides that greatly expand the physicochemical diversity of nucleic acid-based ligands. Such modifications introduce functional groups that are absent in natural nucleic acids but are often found in protein-protein, small molecule-protein, and antibody-antigen interactions. The use of these modifications expands the range of possible targets for SELEX (Systematic Evolution of Ligands by EXponential Enrichment), results in improved binding properties, and facilitates selection of SOMAmers with slow dissociation rates. Our assay works by transforming protein concentrations in a mixture into a corresponding DNA signature, which is then quantified on current commercial DNA microarray platforms. In essence, we take advantage of the dual nature of SOMAmers as both folded binding entities with defined shapes and unique nucleic acid sequences recognizable by specific hybridization probes. Currently, our assay is capable of simultaneously measuring 1,030 proteins, extending to sub-pM detection limits, an average dynamic range of each analyte in the assay of > 3 logs, an overall dynamic range of at least 7 logs, and a throughput of one million analytes per week. Our collection includes SOMAmers that specifically recognize most of the complement cascade proteins. We have used this assay to identify potential biomarkers in a range of diseases such as malignancies, cardiovascular disorders, and inflammatory conditions. In this chapter, we describe the application of our technology to discovering large-scale protein expression changes associated with chronic kidney disease and non-small cell lung cancer. With this new proteomics technology-which is fast, economical, highly scalable, and flexible--we now have a powerful tool that enables whole-proteome proteomics, biomarker discovery, and advancing the next generation of evidence-based, "personalized" diagnostics and therapeutics. Source
SomaLogic | Date: 2014-06-16
A nucleic acid ligand biochip is disclosed, consisting of a solid support to which one or more specific nucleic acid ligands is attached in a spatially defined manner. Each nucleic acid ligand binds specifically and avidly to a particular target molecule contained within a test mixture, such as a bodily fluid. The target molecules include, but are not limited to, proteins (cellular, viral, bacterial, etc.) hormones, sugars, metabolic byproducts, cofactor, and intermediates, drugs, and toxins. Contacting the test mixture with the biochip leads to the binding of a target molecule to its cognate nucleic acid ligand. The biochip may then be contacted with a reagent(s) that reacts covalently with proteins and not with nucleic acids. Each protein target in the test mixture may then detected by detecting the presence of the reagent at the appropriate address on the biochip.
SomaLogic | Date: 2015-01-27
The present disclosure describes the identification and use of aptamers and photoaptamers having slower dissociation rate constants than those obtained using previously described methods. Specifically, the present disclosure describes methods for the identification and use of aptamers to one or more targets within a histological or cytological sample, which have slow rates of dissociation. The aptamers may be used to assess localization, relative density, and presence or absence of one or more targets in cytological and histological samples. Targets may be selected that are specific and diagnostic of a given disease state for which the sample was collected. The aptamers may also be used to introduce target specific signal moieties. In addition to target identification, the aptamers may be used to amplify signal generation through a variety of methods.
SomaLogic | Date: 2015-01-30
The present disclosure describes improved SELEX methods for producing aptamers that are capable of binding to target molecules and improved photoSELEX methods for producing photoreactive aptamers that are capable of both binding and covalently crosslinking to target molecules. Specifically, the present disclosure describes methods for producing aptamers and photoaptamers having slower dissociation rate constants than are obtained using prior SELEX and photoSELEX methods. The disclosure further describes aptamers and photoaptamers having slower dissociation rate constants than those obtained using prior methods. In addition, the disclosure describes aptamer constructs that include a variety of functionalities, including a cleavable element, a detection element, and a capture or immobilization element.
SomaLogic | Date: 2015-09-25
Biomarkers, methods, devices, reagents, systems, and kits used to assess an individual for the prediction of risk of developing a Cardiovascular (CV) Event over a 1 to 5 year period are provided.