D-2-hydroxyisocaproate dehydrogenase Antibody
Description
Definition and Biological Role
D-2-hydroxyisocaproate dehydrogenase is an NAD⁺-dependent enzyme that catalyzes the reversible conversion of D-2-hydroxyacids (e.g., D-2-hydroxyisocaproate) to 2-oxoacids. It belongs to a family of broad-substrate-specificity dehydrogenases found in lactic acid bacteria, such as Lactobacillus delbrueckii subsp. bulgaricus . The antibody against this enzyme is typically developed to:
-
Detect and quantify D-HO-HxoDH expression in bacterial cultures.
-
Investigate enzyme localization and regulation in metabolic pathways.
-
Support structural studies via techniques like Western blotting or immunoprecipitation.
Biochemical Properties and Substrate Specificity
D-HO-HxoDH exhibits broad substrate specificity, favoring aliphatic and aromatic 2-hydroxyacids. Key kinetic parameters for substrates are summarized below:
Table 1: Substrate Specificity of D-HO-HxoDH from Lactobacillus delbrueckii subsp. bulgaricus
| Substrate | Relative Activity (%) |
|---|---|
| D-2-hydroxyisocaproate | 100 |
| D-lactate | 75 |
| D-2-hydroxybutyrate | 68 |
| Glycolate | 12 |
The enzyme shows negligible activity toward branched β-carbon substrates. Its optimal activity occurs at pH 6.0–9.5, with cytochrome c or artificial electron acceptors like DCIP enhancing catalysis .
Gene Cloning and Phylogenetic Analysis
The hdhD gene encoding D-HO-HxoDH was cloned from Lactobacillus delbrueckii subsp. bulgaricus and overexpressed in Escherichia coli . Key findings include:
-
The enzyme shares 60% sequence identity with Lactobacillus casei D-HO-HxoDH and 50–55% identity with bacterial D-lactate dehydrogenases (D-LDHs) .
-
A conserved NAD⁺-binding domain (GXGXXG) is critical for cofactor interaction.
Table 2: Comparative Enzyme Kinetics
| Enzyme Source | Substrate | (μM) | (min⁻¹) |
|---|---|---|---|
| L. bulgaricus D-HO-HxoDH | D-lactate | 164 ± 11 | 65 ± 1.8 |
| Arabidopsis D-LDH | D-lactate | 317 ± 31 | 73 ± 1.7 |
Sources and Research Diversity
-
Industrial Applications: D-HO-HxoDH is engineered for chiral compound synthesis, leveraging its stereospecificity .
-
Medical Relevance: While not directly linked to human disease, its structural homolog D2HGDH (D-2-hydroxyglutarate dehydrogenase) is implicated in D-2-hydroxyglutaric aciduria, a neurometabolic disorder .
-
Antibody Development: Polyclonal antibodies are generated using purified recombinant enzyme, enabling studies on bacterial metabolic adaptation under anaerobic conditions .
Future Directions
Product Specs
**Constituents:** 50% Glycerol, 0.01M PBS, pH 7.4
