Provided are SpdE polypeptides and variants and nucleic acids encoding the SpdE polypeptides and variants. Also provided are vectors including one or more nucleic acids encoding a SpdE polypeptide or variant and cells including a nucleic acid encoding the SpdE polypeptide or variant, as well as cells expressing a SpdE polypeptide or variant and compositions including such cells and a pharmaceutically acceptable carrier. Finally, methods of detecting presence and/or amount of one or more amino acids in a sample are provided. The methods include contacting the sample with a SpdE protein, measuring diguanylate cyclase activity of the SpdE protein; and comparing the diguanylate cyclase activity of the SpdE protein to a control. The methods can utilize isolated SpdE protein or a cell expressing a SpdE protein.

A purifying method includes: illuminating a measurement area with excitation light; detecting fluorescence from the measurement area; measuring an amount of amino acids included in the measurement area, based on an intensity of the fluorescence; and discharging a chemical agent to the measurement area, when the amount of amino acids exceeds a first threshold.

Provided herein are methods and kits for analyzing a biological sample obtained from a subject having, suspected of having, or being at risk for a disease associated with the contact activation system.

An analysis technique can be performed to quantify the digestible protein content of a protein-containing sample outside the body of a living organism. Traditionally, protein digestibility is evaluated in vivo, for example using a rat subject to measure protein digestibility after being fed the protein-containing sample. In some examples, an in vitro technique involves enzymatically digesting the protein-containing sample to simulate digestion that would occur inside a mammalian body. The sample can then be optically analyzed to measure the amount of reactive amine present in the sample, which can provide an indication of the amount of amino acid released during digestion. In some examples, the measured reactive amine value is adjusted to account for the stronger and/or weaker optical response of certain amino acids due to their relative reactivity with an optical tagging agent. Thereafter, an in vivo protein digestibility value can be calculated based on adjusted amine concentration.

A system and method for using new biomarkers to assess individual diseases is provided. In one embodiment of the present invention, absolute quantification of annotated metabolites by mass spectrometry is used to identify certain biomarkers and derivatives thereof (i.e., signatures), which are then used to screen for, diagnose, predict, prognose, and treat various diseases, including, but not limited to, breast cancer, ovarian cancer, colorectal cancer, pancreatic cancer, and acute graft-versus-host disease.

The invention relates to in vivo systems and high throughput screening platform for drugs applicable in inborn error of metabolism (IEM) disorders. More specifically, the invention provides yeast screening system of candidate therapeutic compounds applicable in IEM disorders associated with accumulation of at least one metabolite. The systems of the invention comprise yeast cell/s that carry at least one manipulation in at least one yeast metabolic pathway, that leads to accumulation of said metabolite.

The current disclosure provides a transformative concept based on nanopore technology, Sequencing-by-Hydrolysis, to identify the N-terminal amino acid and the length of each peptide fragment in a peptide ladder to reconstitute the sequence of a protein: a protein/peptide analyte will be nonspecifically hydrolyzed to generate random fragments of the analyte that are different by one amino acid with the N-terminal amino acid of each fragment modified so it generates a distinguishable fingerprint signal when tested by nanopore. The length of the fragment can be estimated by characterizing its translocation signal to back calculate the location of the amino acid in the original analyte. This approach will significantly advance the nanopore technology with single amino acid resolution for protein/peptide sequencing.

Nutritive polypeptides are provided herein. Also provided are various other embodiments including nucleic acids encoding the polypeptides, recombinant microorganisms that make the polypeptides, vectors for expressing the polypeptides, methods of making the polypeptides using recombinant microorganisms, compositions and formulations that comprise the polypeptides, and methods of using the polypeptides, compositions and formulations.

Provided herein are methods and kits for analyzing a biological sample obtained from a subject having, suspected of having, or being at risk for a disease associated with the contact activation system.

Aspects of the disclosure relate to techniques for determining a measure of quantitative loading of a sample in an integrated device. According to some embodiments, there is provided a method for determining a measure of quantitative loading of a sample in an integrated device, the method comprising exciting, with excitation light from at least one excitation source, one or more reference dye molecules that, during the exciting with the excitation light, are attached to respective biomolecules of the sample bound to a surface of a chamber of one or more chambers of the integrated device, obtaining a signal emitted by the one or more reference dye molecules in response to the excitation light, and determining, based on the signal emitted by the one or more reference dye molecules, the measure of quantitative loading of the sample.