Kinetics and specificity of reductive acylation of lipoyl domains from 2-oxo acid dehydrogenase multienzyme complexes.

@article{Graham1989KineticsAS,
  title={Kinetics and specificity of reductive acylation of lipoyl domains from 2-oxo acid dehydrogenase multienzyme complexes.},
  author={Lloyd D. Graham and Len C. Packman and Richard N. Perham},
  journal={Biochemistry},
  year={1989},
  volume={28 4},
  pages={
          1574-81
        }
}
Lipoamide and a peptide, Thr-Val-Glu-Gly-Asp-Lys-Ala-Ser-Met-Glu lipoylated on the N6-amino group of the lysine residue, were tested as substrates for reductive acetylation by the pyruvate decarboxylase (E1p) component of the pyruvate dehydrogenase multienzyme complex of Escherichia coli. The peptide has the same amino acid sequence as that surrounding the three lipoyllysine residues in the lipoate acetyltransferase (E2p) component of the native enzyme complex. Lipoamide was shown to be a very… 

Solution structures of lipoyl domains of the 2-oxo acid dehydrogenase complexes from Azotobacter vinelandii. Implications for molecular recognition.

TLDR
The N-terminal lipoyl domain (79 residues) of the transacetylase component of the pyruvate dehydrogenase complex from Azotobacter vinelandii has been sub-cloned and produced in Escherichia coli, suggesting that the conformation of the lipoyL domain is not altered significantly by the coupled prosthetic group.

Structural determinants of post-translational modification and catalytic specificity for the lipoyl domains of the pyruvate dehydrogenase multienzyme complex of Escherichia coli.

The lipoyl domains of the dihydrolipoyl acyltransferase (E2p, E2o) components of the pyruvate and 2-oxoglutarate dehydrogenase multienzyme complexes are specifically recognised by their cognate 2-oxo

Interaction between the lipoamide-containing H-protein and the lipoamide dehydrogenase (L-protein) of the glycine decarboxylase multienzyme system. 1. Biochemical studies.

TLDR
It is demonstrated that Tris(2-carboxyethyl)phosphine, a specific disulfide reducing agent, allows a continuous reduction of the lipoyl group associated with the H-protein during the course of the reaction catalysed by the L-protein, providing a valuable new tool with which to study the catalytic properties of thelipoamide dehydrogenase.

Recognition of the lipoyl domain is the ultimate determinant of substrate channelling in the pyruvate dehydrogenase multienzyme complex.

TLDR
It is evident that recognition of the protein domain is the ultimate determinant of whether reductive acetylation of the lipoyl group occurs, and that this is ensured by a mosaic of interactions with the Elp.

Reaction mechanism for mammalian pyruvate dehydrogenase using natural lipoyl domain substrates.

TLDR
It is confirmed that the natural E1 reaction, using lipoyl domain acceptors, was completely inhibited by phosphorylation of E1 and theosphorylation strongly inhibited the reverse of the second step catalyzed by E1.

Interaction between the lipoamide-containing H-protein and the lipoamide dehydrogenase (L-protein) of the glycine decarboxylase multienzyme system 2. Crystal structures of H- and L-proteins.

TLDR
The results strongly suggest that a direct interaction between the H- and L-proteins is not necessary for the reoxidation of the reduced lipoamide arm bound to theH-protein.

Specificity Determinants for the Pyruvate Dehydrogenase Component Reaction Mapped with Mutated and Prosthetic Group Modified Lipoyl Domains*

TLDR
Efficient use by mammalian E1 of cognatelipoyl domains derives from unique surface residues with critical interactions contributed by the universal lipoyl-lysine prosthetic group, key specificity residues, and some conserved residues, particularly Asp172 adjacent to Lys173.
...

References

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Amino acid sequence analysis of the lipoyl and peripheral subunit-binding domains in the lipoate acetyltransferase component of the pyruvate dehydrogenase complex from Bacillus stearothermophilus.

The pyruvate dehydrogenase multienzyme complex from Bacillus stearothermophilus comprises a structural core, composed of 60 dihydrolipoamide acetyltransferase (E2p) subunits, which binds multiple

Evidence for two lipoic acid residues per lipoate acetyltransferase chain in the pyruvate dehydrogenase multienzyme complex of Escherichia coli.

TLDR
Evidence is presented to show that the most likely sites of reaction are the lipoic acid residues covalently bound to this component of the pyruvate dehydrogenase multienzyme complex, and this observation can be reconciled with previous determinations of the lipOic acid content of the complex.

Limited proteolysis and sequence analysis of the 2-oxo acid dehydrogenase complexes from Escherichia coli. Cleavage sites and domains in the dihydrolipoamide acyltransferase components.

TLDR
The limited proteolysis data suggest that E2p and E2o possess closer architectural similarities than would be predicted from inspection of their amino acid sequences.

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TLDR
Pulsed-quenched-flow measurements of the rates of the acetylation reactions in the various complexes now demonstrate that the intramolecular transacetylations reactions are not rate-determining in the normal reaction mechanism of the enzyme.

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TLDR
It is clear that active-site coupling is a general property of pyruvate dehydrogenase complexes of octahedral and icosahedral symmetries, the large numbers of subunits in each E2 core enhancing the effect.

Domain structure and 1H-n.m.r. spectroscopy of the pyruvate dehydrogenase complex of Bacillus stearothermophilus.

TLDR
A model of the dihydrolipoamide acetyltransferase chain is proposed in which the small, folded, lipoyl domain comprises the N-terminal region, and the large, foldable, core-forming domain that contains the acetyl transferase active site comprises the C- terminal region.

Limited proteolysis and proton n.m.r. spectroscopy of the 2-oxoglutarate dehydrogenase multienzyme complex of Escherichia coli.

TLDR
Proton nuclear magnetic resonance spectroscopy of the 2-oxoglutarate dehydrogenase complex revealed the existence of substantial regions of polypeptide chain with remarkable intramolecular mobility, most of which were retained after removal of the lipoic acid-containing regions by treatment of the complex with trypsin.

Site-directed mutagenesis and 1H NMR spectroscopy of an interdomain segment in the pyruvate dehydrogenase multienzyme complex of Escherichia coli.

TLDR
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Limited proteolysis and proton NMR spectroscopy of Bacillus stearothermophilus pyruvate dehydrogenase multienzyme complex.

TLDR
Proton nuclear magnetic resonance spectroscopy demonstrated that the enzyme complex contains large regions of polypeptide chain with remarkable intramolecular mobility, most of which were retained after excision of the lipoic-acid-containing regions with chymotrypsin.