CBS
CBS (cystathionine beta-synthase, also known as HIP4) is a hydro-lyase that catalyses the first step of the transsulfuration pathway, converting homocysteine to cystathionine. It also contributes to cellular hydrogen sulfide production. Browse Assay Genie's current range of CBS research reagents below, or read on for the biology behind the target.
CBS is a hydro-lyase that catalyses the first step of the transsulfuration pathway. In a beta-replacement reaction, the hydroxyl group of L-serine is displaced by L-homocysteine to form L-cystathionine, the precursor of L-cysteine. This catabolic route allows the elimination of L-methionine and the toxic metabolite L-homocysteine. CBS is also involved in the production of hydrogen sulfide, a gasotransmitter with signalling and cytoprotective effects on neurons, and the gene is a major contributor to cellular hydrogen sulfide production.
The CBS protein acts as a homotetramer, uses pyridoxal phosphate as a cofactor and is allosterically activated by adenosyl-methionine. It belongs to the cysteine synthase/cystathionine beta-synthase family and is assigned to the carbon-oxygen lyases gene group. UniProt records its subcellular location as the cytoplasm and the nucleus. The CBS gene produces multiple alternatively spliced transcript variants. Mouse and rat each carry a Cbs ortholog, which makes rodent models a common route for studying the enzyme.
Defects in the CBS gene can cause cystathionine beta-synthase deficiency (CBSD), which can lead to homocystinuria. This link between the enzyme and homocysteine handling makes it a central subject in sulfur amino acid metabolism. Researchers studying CBS protein levels, activity or expression often do so alongside other transsulfuration and hydrogen sulfide pathway components. The previous name, cystathionine-beta-synthase, and the alias HIP4 may still appear in older literature.
CBS catalyses the first step of transsulfuration, supporting elimination of L-methionine and L-homocysteine and supplying the precursor of L-cysteine.
CBS is a major contributor to cellular hydrogen sulfide, a gasotransmitter with signalling and cytoprotective effects on neurons.
Defects in the CBS gene cause cystathionine beta-synthase deficiency, which can lead to homocystinuria.
CBS is a pyridoxal phosphate-dependent homotetramer allosterically activated by adenosyl-methionine, making it a model for studying cofactor and allosteric control.
CBS catalyses the first step of the transsulfuration pathway, displacing the hydroxyl group of L-serine with L-homocysteine to form L-cystathionine, the precursor of L-cysteine. It also helps produce hydrogen sulfide, a gasotransmitter with signalling and cytoprotective effects on neurons.
CBS is also known as HIP4, and its previous name was cystathionine-beta-synthase. The enzyme is EC 4.2.1.22 and acts as a homotetramer with pyridoxal phosphate as cofactor. Multiple alternatively spliced transcript variants have been reported for the gene.
Defects in CBS cause cystathionine beta-synthase deficiency (CBSD), which can lead to homocystinuria. Mouse and rat both have a Cbs ortholog; check the datasheet of any product for its validated reactivity.
Other sulfur amino acid metabolism and hydrogen sulfide pathway targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P35520; product specifications from Assay Genie datasheets.