Peptide and/or protein quantitation methods, kits, and compositions, particularly useful for mass spectrometry, are provided herein based on a bathocuproine-based composition complex such as bathocuproinedisulfonic acid disodium salt hydrate complex. The methods are one-step rapid absorbance methods using small sample volumes. They produce a robust signal with high signal to background ratio and accurately quantitate even complex peptide mixtures with low variability and high sensitivity.

A method for detecting presence of protein or biofilm on a surface includes applying a composition to the surface, and observing a color reaction if protein or biofilm is present on the surface. The composition comprises a first part that includes copper sulfate and a second part that includes a reagent capable of reacting with the copper sulfate to produce a visible color reaction when contacted with protein or biofilm.

Chemoproteomic methods for detecting and profiling electrophilic post-translational modifications (PTMs) and oxidative PTMs in proteins are described. The methods including contacting a proteomic mixture with a probe having hydrazine and alkyne moieties or oxyamine and alkyne moieties to form a covalent linkage between the hydrazine or oxyamine moiety of the probe and the electrophilic PTM or oxidative PTM of the protein. The resulting alkyne-derivatized proteins are labelled with an azide modified tag via a click chemistry reaction. The labelled proteins can then be detected or profiled using techniques such as, for example, fluorescence imaging or mass spectrometry. Also described are protein conjugates having a covalent linkage formed by reaction of a hydrazine or oxyamine moiety of a probe with an electrophilic or oxidative PTM of a protein.

Peptide and/or protein quantitation methods, kits, and compositions, particularly useful for mass spectrometry, are provided herein based on a bathocuproine-based composition complex such as bathocuproinedisulfonic acid disodium salt hydrate complex. The methods are one-step rapid absorbance methods using small sample volumes. They produce a robust signal with high signal to background ratio and accurately quantitate even complex peptide mixtures with low variability and high sensitivity.

Chemoproteomic methods for detecting and profiling electrophilic post-translational modifications (PTMs) and oxidative PTMs in proteins are described. The methods including contacting a proteomic mixture with a probe having hydrazine and an affinity handle to form a covalent linkage between the hydrazine moiety of the probe and the endogenous electrophilic PTM or the endogenous oxidative PTM. The resulting derivatized proteins are labelled with an tag via a click chemistry reaction. The labelled proteins can then be detected or profiled using techniques such as, for example, fluorescence imaging or mass spectrometry. Also described are protein conjugates having a covalent linkage formed by reaction of a hydrazine or oxyamine moiety of a probe with an electrophilic or oxidative PTM of a protein.

Biochemical test methods for protein quantification can include application of foam-suppressing and/or foam-destroying substances to avoid readout problems and ensure the accuracy of measurement results. One such method for determining the amount of one or more proteins in a solution includes providing at least a first solution that is known to contain or suspected of containing one or more protein(s), adding at least one foam-suppressing and/or foam-destroying substance to the first solution, resulting in a second solution, and determining the amount of the one or more protein(s) in the second solution.

Biochemical test methods for protein quantification can include application of foam-suppressing and/or foam-destroying substances to avoid readout problems and ensure the accuracy of measurement results. One such method for determining the amount of one or more proteins in a solution includes providing at least a first solution that is known to contain or suspected of containing one or more protein(s), adding at least one foam-suppressing and/or foam-destroying substance to the first solution, resulting in a second solution, and determining the amount of the one or more protein(s) in the second solution.

This disclosure relates to methods of diagnosing and treating a copper metabolism-associated disease or disorder, such as Wilson disease (WD).

Peptide and/or protein quantitation methods, kits, and compositions, particularly useful for mass spectrometry, are provided herein based on a bathocuproine-based composition complex such as bathocuproinedisulfonic acid disodium salt hydrate complex. The methods are one-step rapid absorbance methods using small sample volumes. They produce a robust signal with high signal to background ratio and accurately quantitate even complex peptide mixtures with low variability and high sensitivity.

Peptide and/or protein quantitation methods, kits, and compositions, particularly useful for mass spectrometry, are provided herein based on a bathocuproine-based composition complex such as bathocuproinedisulfonic acid disodium salt hydrate complex. The methods are one-step rapid absorbance methods using small sample volumes. They produce a robust signal with high signal to background ratio and accurately quantitate even complex peptide mixtures with low variability and high sensitivity.