High impact information on Dbt

• In the present study, we report that the 56 kD antigen is the protein X of pyruvate dehydrogenase complex and that it possesses cross-reactive antimitochondrial autoantibody epitope(s) with the 74 kD antigen, the acetyltransferase (E2) of the pyruvate dehydrogenase complex [1].
• Structure of the gene encoding dihydrolipoyl transacylase (E2) component of human branched chain alpha-keto acid dehydrogenase complex and characterization of an E2 pseudogene [2].
• In addition, a lipoate-free inner E2 core consisting of fragment A (Mr = 26,000) and fragment B (Mr = 22,000) was produced [3].
• To characterize the lipoyl-bearing domain of the dihydrolipoyl transacylase (E2) component, purified branched-chain alpha-keto acid dehydrogenase complex from bovine liver was reductively acylated with [U-14C] alpha-ketoisovalerate in the presence of thiamin pyrophosphate and N-ethylmaleimide [3].
• Previous studies showed that the epitopes aa481-500 and aa551-570 of E2 might be important for immunoreactivity and that the binding site of E2 for hCD81 is located at aa480-493 and aa544-551 within the E2 protein [4].

Biological context of Dbt

• Isolation of the murine branched-chain alpha-ketoacid dehydrogenase E2 subunit promoter region [5].
• In the region encoding the mature E2 subunit protein, both the nucleotide composition and predicted amino acid sequence are highly conserved between murine, human, and bovine species [6].
• Sequence analysis of the promoter-regulatory region showed the presence of two inverted 'CAAT box' sequences, the most proximal being -42 to -48 bp upstream from the determined transcription initiation site, but no TATA-box sequences, similar to the human BCKAD E2 gene [5].
• Here, we made plasmids containing genes encoding either wild type or mutant E2 proteins in which N-glycosylation sites (N560NT and N576ST) close to these important regions were mutated separately or in combination [4].
• Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response in piglets [7].

Analytical, diagnostic and therapeutic context of Dbt

• Molecular cloning of the murine branched chain alpha-ketoacid dehydrogenase E2 subunit: presence of 3' B1 repeat elements [6].
• Mouse antiserum against E2 reacted only with fragments L1, L2, and L3, and did not bind fragments L4, L5, A, and B as judged by immunoblotting analysis [3].
• The immunogenicities of wild type E2 and three mutated E2 proteins were analyzed in BALB/c mice using DNA vaccination [4].
• Similarly, addition of exogenous E2 peptide to fetal thymic organ culture resulted in efficient deletion of double-positive thymocytes [8].
• RESULTS: Intradermal injection of E2 DNA vaccine induced strong Th1-like immune responses in mice [7].

References