Dehydrogenase lipoamide

Bastiaens, P. I. H., van Hoek, A., Benen, J. A., Brochon, J. C. and Visser, A. J. W. G. (1992). Conformational dynamics and intersubunit energy transfer in wild-type and mutant lipoamide dehydrogenase from Azotobacter vinelandii. A multidimensional time-resolved polarized fluorescence study. Biophys. J. 63, 839-53. 

A. J. W. G. Visser, H. J. Grande, and C. Veeger, Rapid relaxation processes in pig heart lipoamide dehydrogenase revealed by subnanosecond resolved fluorometry, Biophys. Chem. 12, 35-49 (1980). 

Scheme 3.2 Cofactor regeneration using copolymerized mediator and lipoamide dehydrogenase at an electrode surface [51].

In an early report to a process using three oxidoreductases, namely hydrogenase (ECl.12.2.1), lipoamide dehydrogenase (EC 1.6.4.3) and 20(3-hydroxysteroid dehydrogenase (ECl.1.1.53), a reverse micelle system was used to facilitate stereo- and site-specific reduction of apolar ketosteroids, assisted by the in situ NADH-regenerating enzyme system [61]. 

Isoleucine MSUD Lipoamide dehydrogenase deficiency Severe protein malnutrition... 

Dihydrolipoyl dehydrogenase (lipoamide dehydrogenase), glutathione reductase, and human thioredoxin reductase187 190 belong to a subclass... 

There are two 2-oxoacid dehydrogenase multienzyme complexes in E. coli. One is specific for pyruvate, the other for 2-oxoglutarate. Each complex is about the size of a ribosome, about 300 A across. The pyruvate dehydrogenase is composed of three types of polypeptide chains El, the pyruvate decarboxylase (an a2 dimer of Mr — 2 X 100 000) E2, lipoate acetyltransferase (Mr = 80 000) and E3, lipoamide dehydrogenase (an a2 dimer of Mr = 2 X 56 000). These catalyze the oxidative decarboxylation of pyruvate via reactions 1.6, 1.7, and 1.8. (The relevant chemistry of the reactions of thiamine pyrophosphate [TPP], hydroxyethylthiamine pyrophosphate [HETPPJ, and lipoic acid [lip-S2] is discussed in detail in Chapter 2, section C3.)... 

Enzymes in the cross-linked crystal form are essentially impervious to degradation by exogenous proteases and from autolysis, in the case of CLCs of proteases themselves [5], This stability makes the enzyme-catalyzed preparation of peptides and peptide mimics truly practical [6], Examples will be discussed in more detail in Sec. IV. Further, one could conceive of using multiple enzymes in one-pot reaction systems mimicking natural biosynthetic cascades. Indeed, the application of this concept has been reported for a mixture of lipoamide dehydrogenase and lactate dehydrogenase [19],... 

Cadmium in the body is known to affect several enzymes. It is believed that the renal damage that results in proteinuria is the result of cadmium adversely affecting enzymes responsible for reabsorption of proteins in kidney tubules. Cadmium also reduces the activity of delta-aminolevulinic acid synthetase (Figure 10.3), arylsulfatase, alcohol dehydrogenase, and lipoamide dehydrogenase, whereas it enhances the activity of delta-aminolevulinic acid dehydratase, pyruvate dehydrogenase, and pyruvate decarboxylase. 

TABLE 11.5. Search Result of AACompIdent for Lipoamide Dehydrogenase from... 

Figure 12.18. Output of Pfam search results. Pfam search is performed with amino acid sequence derived from lipoamide dehydrogenase (Schizosaccharomyces pombe). The table for the trusted matches from Pfam-A for pyr redox (pyridine nucleotide disulfide oxidoreductase) and pyr redox dim (pyridine nucleotide disulfide oxidoreductase, dimerization) domains and their alignments (partial) to HMMs ( ->) are shown. The trusted matches from Pfam-B, the potential matches (Thi4 for thiamine biosynthetic enzyme domain), and the bead-on-a-string sketches are not shown. Select the linked domain name to view the functional description of the domain. The HMM alignments are followed by an option button (Align to seed or Align to family) that enables the user to view/save the multiple alignment of each matched family.

The absence in halobacteria of the oxoacid dehydrogenase complexes creates another puzzle. In most known systems, the role of the enzyme lipoamide dehydrogenase is to reoxidize the lipoic acid that is involved in the oxidation of the oxoacids in the oxoacid dehydrogenase complexes. This enzyme was nonetheless found in H. halobium and purified to homogeneity by Danson et al. (1986). What, then, is its function It is likely that lipoamide dehydrogenase assumes a different role in halobacteria. Another reducing system unique to... 

Fig. 21 l-LDH catalyzed reduction of pyruvate coupled with regeneration of NADH based on electrochemical reduction of disulfides. LipDH Lipoamide Dehydrogenase DTT Dithiothreitol Lip Lipoamide (R = (CH2)4CONH2)... 

Limitations of the system are the low turnover numbers as well as the failure to regenerate NADPH. However, if ferredoxin reductase is used for coenzyme regeneration instead of lipoamide dehydrogenase, this method can also be applied to NADP+-dependent systems [97]. 

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