US 8,476,034 B2 · Methods and compositions for assaying homocysteine

Abstract

This invention relates generally to the field of homocysteine detection. In particular, the invention provides a method for determining homocysteine presence or concentration in samples, which method comprises: contacting a sample containing or suspected of containing Hcy with a Hcy co-substrate and a Hcy converting enzyme in a Hcy conversion reaction to form a Hcy conversion product and a Hcy co-substrate conversion product; and assessing the Hcy co-substrate conversion product to determine the presence, absence and/or amount of the Hcy in the sample. The Hcy co-substrate conversion product may be assessed directly, or it may be assessed by further conversion of the Hcy co-substrate conversion product into another material by the action of one or more additional enzymes. A kit for assaying homocysteine based on the same principle is also provided.

Claims20

Dependent claims

A method for assaying homocysteine (Hcy) in a sample without chromatographic separation, which method comprises:

a) contacting a sample containing or suspected of containing Hcy with a Hcy co-substrate and a Hcy converting enzyme in a Hcy conversion reaction to form a Hcy conversion product and a Hcy co-substrate conversion product, wherein the Hcy co-substrate is S-adenosylmethionine (SAM), the Hcy converting enzyme is a S-adenosylmethionine (SAM)-dependent homocysteine S-methyltransferase, the Hcy conversion product is methionine (Met) and the Hcy co-substrate conversion product is S-adenosyl-L-homocysteine (SAH);
b) contacting the mixture formed in step a) with an adenosylhomocysteine nucleosidase to convert SAH into adenine and S-ribosyl homocysteine;
c) contacting the mixture formed in step b) with an S-ribosyl homocysteinase to cycle the S-ribosyl homocysteine into homocysteine;
and
d) assessing the amount of adenine in the mixture formed in step b) and/or c),
whereby the amount of Hcy in the sample is determined from the amount of adenine.

3 more elements

Dependencies are inferred from the claim text.

Methods and compositions for assaying homocysteine

Life of this patent

Methods and compositions for assaying homocysteine

Life of this patent

Abstract

Claims20