Provided is a compound comprising the structure:

(SIG)-(SI-MOD).sub.m.

In this compound, SIG is a signaling molecule, SI is a self-immolative structure bound to SIG such that SIG has a reduced signal relative to the signal of SIG without SI, MOD is a moiety bound to SI that is subject to modification by an activator, and m is an integer from 1 to about 10. With this compound, when MOD is modified by an activator, SI is destabilized and self-cleaved from SIG such that SIG generates an increased signal. Also provided is a method of determining whether a sample comprises an activator, using the above-described compound. Additionally provided is a method of determining whether a cell comprises a nitroreductase using the above-described compound where nitroreductase is the activator. Further provided is a method of determining whether a mammalian cell is hypoxic using the above-described compound where nitroreductase is the activator. A method of detecting a microorganism that comprises a nitroreductase, using the above-described compound where nitroreductase is the activator, is also provided. Also provided is a method of identifying nitroreductase in a sample, using the above-described compound where nitroreductase is the activator.

A method and system for sensing or characterizing a biomarker, such as a proteolytic enzyme or nucleic acid. The system comprises a nanopore sensor to determine a current modulation of a sample including a biomarker, and a predetermined substrate or nucleic acid probe current modulation signature for comparison to a current signature from the nanopore sensor. The nanopore sensor includes a nanopore membrane between two fluid compartments, and a power supply in electrical contact with the membrane to provide an electric potential difference between the fluid compartments. A detector is used to detect an electrical current through the nanopore as the polypeptide substrate, or components thereof, transits the nanopore under an applied electric potential difference between the first and second fluid compartments. The result is a rapid, label-free method for the sensitive and accurate measurement of biomarker activity by real-time monitoring of the ionic current modulations arising from the substrate peptide-protease interactions or nucleic acid hybridization in the nanopore.

A method and system for sensing or characterizing a biomarker, such as a proteolytic enzyme or nucleic acid. The system comprises a nanopore sensor to determine a current modulation of a sample including a biomarker, and a predetermined substrate or nucleic acid probe current modulation signature for comparison to a current signature from the nanopore sensor. The nanopore sensor includes a nanopore membrane between two fluid compartments, and a power supply in electrical contact with the membrane to provide an electric potential difference between the fluid compartments. A detector is used to detect an electrical current through the nanopore as the polypeptide substrate, or components thereof, transits the nanopore under an applied electric potential difference between the first and second fluid compartments. The result is a rapid, label-free method for the sensitive and accurate measurement of biomarker activity by real-time monitoring of the ionic current modulations arising from the substrate peptide-protease interactions or nucleic acid hybridization in the nanopore.

The present application provides compositions and methods for determining a disease or condition in a subject. The method comprises contacting a body fluid with a molecule comprising a reporter thereof and the reported is cleaved by an agent in the body fluid. Diseases and conditions that can be determined by the method are also described.

The present application provides compositions and methods for determining a disease or condition in a subject. The method comprises contacting a body fluid with a molecule comprising a reporter thereof and the reported is cleaved by an agent in the body fluid. Diseases and conditions that can be determined by the method are also described.

A method of making a polypeptide including at least one covalent bond between a pair of reactive side chains of corresponding amino acids, wherein the covalent bond is insensitive to reduction is provided including genetically modifying a genomically recoded organism to express a corresponding synthetase, tRNA or synthetase/tRNA pair for translating mRNA encoding the corresponding amino acids having the reactive side chains into the polypeptide and to express the polypeptide including the at least one pair of the reactive side chains wherein the reactive side chains are oriented near one another when the expressed polypeptide is in a folded configuration, wherein the reactive side chains react to form the covalent bond that is insensitive to reduction.

New use of ADAMTS13 in the clinical filed is provided. The use of ADAMTS13 as a biomarker for monitoring the onset of liver damage, hepatic ischemia/reperfusion injury or the liver function after liver transplantation: a method of testing liver damage, a method of testing hepatic ischemia/reperfusion injury, or a method of testing the liver function after liver transplantation, each of the methods comprising measuring or monitoring the ADAMTS13 activity in a sample from a mammal; an agent for treating diseases selected from the group consisting of liver damage, hepatic ischemia/reperfusion injury and hepatic dysfunction after liver transplantation, which comprises ADAMTS13 or a mutant of ADAMTS13 as an effective ingredient.

The present specification discloses SNAP-25 compositions, methods of making α-SNAP-25 antibodies that bind an epitope comprising a carboxyl-terminus at the P.sub.1 residue from the BoNT/A cleavage site scissile bond from a SNAP-25 cleavage product, α-SNAP-25 antibodies that bind an epitope comprising a carboxyl-terminus at the P.sub.1 residue from the BoNT/A cleavage site scissile bond from a SNAP-25 cleavage product, methods of detecting BoNT/A activity, and methods of detecting neutralizing α-BoNT/A antibodies.

The present specification discloses SNAP-25 compositions, methods of making α-SNAP-25 antibodies that bind an epitope comprising a carboxyl-terminus at the P.sub.1 residue from the BoNT/A cleavage site scissile bond from a SNAP-25 cleavage product, α-SNAP-25 antibodies that bind an epitope comprising a carboxyl-terminus at the P.sub.1 residue from the BoNT/A cleavage site scissile bond from a SNAP-25 cleavage product, methods of detecting BoNT/A activity, and methods of detecting neutralizing α-BoNT/A antibodies.

A method for measuring a glycated protein in a sample, the method comprising (1) a step of allowing a sample in which a degradation product has been generated from a glycated protein by a protease to react with an oxidoreductase in the presence of an electron mediator to generate a reduced electron mediator; and (2) a step of detecting the reaction state in the step (1) by an electrochemical technique using an interdigitated electrode.