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PubMed1992

Crystallization and preliminary X-ray diffraction studies of mitochondrial short-chain delta 3,delta 2-enoyl-CoA isomerase from rat liver.

Crystals of short-chain delta 3,delta 2-enoyl-CoA isomerase (EC 5.3.3.8) from rat liver mitochondria have been grown using the hanging-drop vapour diffusion technique. The enoyl-CoA isomerase is an auxiliary enzyme in the beta-oxidation pathway of fatty acid metabolism, and catalyzes the isomerization of unsaturated fatty acids to produce the metabolizable delta 2-trans isomer. The crystals belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions a = 47.9, b = 118.4 and c = 164.8 A, and diffract to 3 A.

Animals↗

PubMed1994

Purification and mechanism of delta 3,delta 5-t-2,t-4-dienoyl-CoA isomerase from rat liver.

A new enzyme, i.e., delta 3,delta 5-t-2,t-4-dienoyl-CoA isomerase, required in the NADPH-dependent metabolic pathway of odd-numbered double bond, unsaturated fatty acids, was isolated and purified to apparent homogeneity from rat liver. In the oxidation of odd-numbered double bond, unsaturated fatty acids, stepwise beta-oxidation leads to cis-5-enoyl-CoA, which is then dehydrogenated and isomerized to delta 3,delta 5-dienoyl-CoA. delta 3,delta 5-t-2,t-4-Dienoyl-CoA isomerase converts delta 3,delta 5-dienoyl-CoA to trans-2,trans-4-dienoyl-CoA, which is a substrate for NADPH-dependent 2,4-dienoyl-CoA reductase. This enzyme was purified through Matrex gel red A, blue Sepharose, DEAE-cellulose, CM-cellulose, hydroxylapatite, and Sepharose CL6B column chromatography of an ammonium sulfate precipitated fraction (30-80%) of rat liver homogenate. A native molecular weight of 200,000 with four subunits of 55,000 each was determined. The isoelectric point was 6.5. This enzyme was located in mitochondria and was inducible by clofibrate treatment. Using delta 3,delta 5-decadienoyl-CoA, delta 3,delta 5-dodecadienoyl-CoA, and delta 3,delta 5-tetradecadienoyl-CoA as substrates, the Vmax ratio was 1:0.5:0.4 and the Km's were 10.9, 5.9, and 1.4 microM, respectively. The specific activity of purified enzyme was 7 units/mg using delta 3,delta 5-decadienoyl-CoA as substrate. The mechanism of isomerization was studied by deuterium labeling. Consistent with the deuterium labeling pattern of the products, the isomerization from trans-2,cis-5-dienoyl-CoA to trans-2,trans-4-dienoyl-CoA was a two-step process through an intermediate delta 3,delta 5-dienoyl-CoA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Delta 3, delta 2-enoyl-CoA isomerase is the protein that copurifies with human glutathione S-transferases from S-hexylglutathione affinity matrices.

An unidentified 30 kDa protein frequently copurifies with human glutathione S-transferases from S-hexyl-glutathione affinity matrices. Application of two-step sequential affinity chromatographic methods yielded a homogeneous preparation of that protein from human liver specimens. The protein was digested with Achromobacter protease I, and sequences of peptides resolved by h.p.l.c. showed a high degree of identity with those of rat mitochondrial delta 3, delta 2-enoyl-CoA isomerase. The human protein also exhibited catalytic activity with delta 3-cis-octenyl CoA as a substrate. Thus it is identified as liver delta 3, delta 2-enoyl-CoA isomerase.

Adult↗

PubMed1998

The peptidyl-prolyl isomerase domain of the CyP-40 cyclophilin homolog Cpr7 is not required to support growth or glucocorticoid receptor activity in Saccharomyces cerevisiae.

CyP-40 cyclophilins are found in association with molecular chaperone Hsp90.steroid receptor complexes. The amino-terminal portion of these cyclophilins harbors the characteristic peptidyl-prolyl isomerase (PPIase) domain, whereas three copies of the tetratricopeptide (TPR) motif, a structure shown to be involved in protein-protein interactions, and a putative calmodulin-binding domain are located in the carboxyl-terminal half of the protein. The TPR domains mediate binding to Hsp90, but a requirement for the PPIase domain has not been established. To address this, we have investigated the effects of mutations that alter the PPIase domain of the Saccharomyces cerevisiae CyP-40 homolog, Cpr7. Because Cpr7 is required for rapid growth and full Hsp90 activity, a functional assessment of the PPIase domain could be performed in vivo. A mutation in the catalytic domain altering a conserved site predicted to be essential for isomerase activity did not compromise Cpr7 function. Furthermore, deletion of the entire PPIase domain did not significantly affect growth or Hsp90-mediated steroid receptor activity. These results indicate that the TPR-containing carboxyl terminus of Cpr7 is sufficient for fundamental Cpr7-dependent activity.

Carrier Proteins↗

PubMed1994

Cloning and characterization of ppiB, a Bacillus subtilis gene which encodes a cyclosporin A-sensitive peptidyl-prolyl cis-trans isomerase.

Sequencing of N-terminal and internal peptide fragments of the purified 17 kDa Bacillus subtilis peptidyl-prolyl cis-trans isomerase (PPIase) revealed sequence identity to conserved regions of a number of eukaryotic and prokaryotic cyclophilins. Using two oligonucleotide primers corresponding to the N-terminus and a highly conserved internal amino acid sequence, polymerase chain reactions (PCR) with B. subtilis genomic DNA were carried out. The resultant PCR fragment of 335 bp was cloned, sequenced and subsequently used as a probe for screening a lambda Zap II gene library of B. subtilis. Two overlapping positive clones of 5 and 7 kb containing the B. subtilis PPIase gene (ppiB), which is 432 bp in length and encodes a protein of 144 amino acid residues, were identified and two distinct transcriptional initiation sites at the 5' end of ppiB were mapped. The entire region (35 kb) between spoVA and serA was recently sequenced in B. subtilis, and an open reading frame (ORF) that encodes a putative peptidyl-prolyl cis-trans isomerase at about 210 degrees on the B. subtilis genetic map was located. This putative PPIase is identical to PPiB. We have overexpressed the ppiB gene in Escherichia coli, purified the encoded protein to apparent homology and shown that it exhibits PPIase activity. In addition, the recombinant PPiB shows a significant inhibition of PPIase activity by cyclosporin A (CsA) at a level comparable to that observed for the B. subtilis enzyme. Interestingly the B. subtilis PPIase shows about 40% identity to eukaryotic PPIases and less similarity to those of Gram-negative bacteria (27-32% identity). Like other interruption mutants of yeast and Neurospora, which lack a functional cyclophilin gene, a B. subtilis mutant containing ppiB::cat, a cat-interrupted copy of ppiB in the chromosome, is viable.

Amino Acid Isomerases↗

PubMed1994

Domains of the tetrafunctional protein acting in glyoxysomal fatty acid beta-oxidation. Demonstration of epimerase and isomerase activities on a peptide lacking hydratase activity.

Peroxisomes from different eukaryotic organisms house a multifunctional protein acting in fatty acid beta-oxidation. In plant glyoxysomes, one of the isoforms of this protein contains the activities of L-3-hydroxyacyl-CoA hydrolyase (EC 4.2.1.17), L-3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.211), D-3-hydroxyacyl-CoA epimerase, and delta 3,delta 2-enoyl-CoA isomerase (EC 5.3.3.8). This was demonstrated after molecular cloning of a cDNA coding for a protein of 79047 Da and its bacterial expression. Chromatographic purification yielded a monomeric protein exhibiting all four activities. In addition, mutant forms were prepared, and peptides representing single domains were purified. Peptides containing the N-terminal region showed D-3-hydroxyacyl-CoA epimerase and delta 3,delta 2-enoyl-CoA isomerase activities but lacked 2-trans-enoyl-CoA hydratase and L-3-hydroxyacyl-CoA dehydrogenase activities. Using the N-terminal fragment, we demonstrated that the D-3-hydroxyacyl-CoA converting activity is actually an epimerase rather than part of a combined water eliminating and water attaching system. The C-terminal half of the multifunctional protein represents the dehydrogenase domain.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMed1994

Effects of CaBP2, the rat analog of ERp72, and of CaBP1 on the refolding of denatured reduced proteins. Comparison with protein disulfide isomerase.

It has been shown previously that CaBP2, the rat analog of the murine protein ERp72, and CaBP1, the rat analogue of the hamster protein P5, represent members of the protein disulfide isomerase (PDI) family and are able to catalyze the reduction of insulin in the presence of various reductants (Nguyen Van et al., 1993). We have now examined the abilities of CaBP2 and CaBP1 to catalyze the renaturation of denatured reduced model proteins. Both CaBP2 and CaBP1 catalyzed the reappearance of the biological activity of the denatured reduced Fab fragment of a monoclonal anti-human creatine phosphokinase antibody. The reaction rate was positively correlated with the amount of CaBP2 or CaBP1 and dependent on the GSH/GSSG ratio (maximum at GSH/GSSG = 1). Peptide prolyl-cis,trans-isomerase (PPI), which catalyzed some renaturation on its own, showed synergistic effects with PDI, CaBP2, and CaBP1. No synergistic effects could be observed when the combinations CaBP2 + PDI, CaBP1 + PDI, or CaBP2 + CaBP1 were tested. Variation of [Ca2+] between 0 and 1 mM did not have any effect on the rate or amount of renaturation catalyzed by CaBP2, CaBP1, or PDI, nor were these parameters affected by the simultaneous presence of BiP or grp94. Both CaBP2 and CaBP1 catalyzed also the renaturation of denatured reduced ribonuclease AIII in a way that depended on the amounts of CaBP2 or CaBP1 and on the redox potential of the redox system used (GSH/GSSG or CSH/CSSC). PPI alone had no effect on the rate of RNase AIII renaturation and did not significantly affect renaturation catalyzed by PDI, CaBP2, or CaBP1. PDI showed a moderate but significant synergism with CaBP2, and a strong synergism with CaBP1. The results indicate that both CaBP2 and CaBP1 can catalyze the formation of disulfide bonds and protein disulfide isomerization and may thus be involved in the folding of nascent proteins in the secretory pathway. This does not exclude the possibility of additional functions of these proteins in the pre-Golgi compartments.

Animals↗

PubMed2000

CHILD syndrome caused by deficiency of 3beta-hydroxysteroid-delta8, delta7-isomerase.

CHILD (congenital hemidysplasia, ichthyosis, and limb defects) syndrome is a rare, usually sporadic disorder associated with unilateral distribution of ichthyosiform skin lesions, limb defects, punctate calcifications of cartilaginous structures, and visceral anomalies. CHILD syndrome shares some manifestations with X-linked dominant Conradi-Hünermann syndrome (CDPX2), although the skeletal defects and skin lesions in CDPX2 are bilateral and asymmetric. Because CDPX2 patients have abnormal 8-dehydrosterol metabolism caused by mutations in 3beta-hydroxysteroid-delta8,delta7-isomerase, we measured plasma sterols in a patient with CHILD syndrome and found levels of 8-dehydrocholesterol and 8(9)-cholestenol increased to the same degree as in CDPX2 patients. Subsequently, we identified a nonsense mutation in exon 3 of the patient's 3beta-hydroxysteroid-delta8,delta7-isomerase gene. We speculate that at least some cases of CHILD syndrome are allelic with CDPX2 caused by 3beta-hydroxysteroid-delta8,delta7-isomerase deficiency.

Abnormalities, Multiple↗

PubMed1986

Isolation and molecular analysis of the phosphoglucose isomerase structural gene of Saccharomyces cerevisiae.

The PGI1 gene of Saccharomyces cerevisiae coding for the glycolytic enzyme phosphoglucose isomerase has been cloned by complementation of a mutant strain (pgi1) with a strongly reduced phosphoglucose isomerase activity. A genomic library constructed in the yeast multicopy vector YEp13 (Nasmyth and Tatchell 1980) was used. Four plasmids containing an overlapping region of 4.1 kb were isolated and characterized by restriction endonuclease mapping. Southern analysis of genomic digests prepared with different restriction enzymes confirmed the same pattern for the chromosomal sequences. Transformants with the isolated plasmids had a phosphoglucose isomerase activity increased by a factor of 7. The cloned sequence hybridized to a constitutively synthesized 2.2 kb RNA in Northern analysis. The coding region includes a 2.05 kb EcoRI fragment common to all four inserts. A fragment including part of the PGI1 region was subcloned into vector YRp7 and used to induce integration at the PGI1 locus. Genetical and Southern analysis of stable transformants showed that single as well as tandem integration took place at this locus. This showed that the PGI1 gene had been isolated. Finally, and in contrast to the results of Kempe et al. (1974a, b) who reported three isoenzymes in yeasts, only one copy of the PGI1 gene per genome was found in several laboratory strains tested by Southern analysis.

Cloning, Molecular↗

PubMed2004

First bacterial chalcone isomerase isolated from Eubacterium ramulus.

The human fecal anaerobe Eubacterium ramulus is capable of degrading various flavonoids, including the flavone naringenin. The first step in the proposed degradation pathway is the isomerization of naringenin to the corresponding chalcone. Cell-free extracts of E. ramulus displayed chalcone isomerase activity. The enzyme from E. ramulus was purified to homogeneity. Its apparent molecular mass was estimated to be 136 and 129 kDa according to gel filtration and native polyacrylamide gel electrophoresis, respectively. Chalcone isomerase is composed of one type of subunit of 30 kDa. The purified enzyme catalyzed the isomerization of naringenin chalcone, isoliquiritigenin, and butein, three chalcones that differ in their hydroxylation pattern. N-bromosuccinimide, but also naringenin and phloretin, inhibited the purified enzyme considerably. This is the first report on a bacterial chalcone isomerase. The physiological function of the purified enzyme is unclear, but an involvement in the conversion of the flavanone naringenin to the chalcone is proposed.

Bromosuccinimide↗

PubMed1990

Basic fibroblast growth factor inhibits delta 5-3 beta-hydroxysteroid dehydrogenase-isomerase activity in cultured immature Leydig cells.

Basic fibroblast growth factor inhibited basal delta 5-3 beta-hydroxysteroid dehydrogenase-isomerase activity in cultured Leydig cells from immature rats in a concentration- and time-dependent manner. Maximal inhibition was achieved with 5-10 ng/ml basic fibroblast growth factor following approximately 48 h of exposure. The inhibition of basal delta 5-3 beta-hydroxysteroid dehydrogenase-isomerase activity was not altered by human chorionic gonadotropin; however, cycloheximide (0.5-2.0 micrograms/ml) partially reversed the effects of basic fibroblast growth factor in a dose-dependent manner. These studies suggest that locally-produced basic fibroblast growth factor may modulate Leydig cell testosterone formation by regulating delta 5-3 beta-hydroxysteroid dehydrogenase-isomerase activity.

3-Hydroxysteroid Dehydrogenases↗

PubMed1986

3 beta-hydroxysteroid isomerase dehydrogenase in guinea-pig kidney: possible involvement in 11-deoxycorticosterone formation in situ.

3 beta-Hydroxysteroid isomerase dehydrogenase, capable of acting on C21- and C19-3 beta-hydroxy-5-ene-steroids has been found in guinea-pig kidney at equivalent levels to those in guinea pig testes. Of the 3 beta-hydroxy-5-ene-steroids present in guinea pig serum, 21-hydroxypregnenolone occurs in highest concentration (17 nM) followed by pregnenolone (10 nM), whereas 17 alpha-hydroxy-pregnenolone and dehydroepiandrosterone occur in very low concentrations (less than 0.5 nM). Furthermore, the concentration of 21-hydroxypregnenolone relative to 11-deoxycorticosterone (the mineralocorticoid of the guinea pig), is 10:1 (Nishikawa and Strott, Steroids 41 (1983) 105-120). The apparent Km value for 21-hydroxypregnenolone, for the reaction yielding 11-deoxycorticosterone as catalysed by guinea pig kidney microsomes, was 85 nM and the Vmax 33 pmol/min per mg protein. Pregnenolone was a competitive inhibitor (apparent Ki = 5 microM) in the above reaction. A sex difference in the level of the enzyme in the kidney was found (activity in the female was one-third of that in the male) which may indicate that the enzyme is under partial androgen control. 3 beta-Hydroxysteroid isomerase dehydrogenase activity was also detected in guinea pig liver and again it was lower in the female. Whilst the exact role of 3 beta-hydroxysteroid isomerase dehydrogenase in guinea-pig kidney remains uncertain, the data suggest that it may utilise blood-borne 21-hydroxypregnenolone, the later then playing the role of a prohormone.

17-Hydroxysteroid Dehydrogenases↗

PubMed2003

Distinct sucrose isomerases catalyze trehalulose synthesis in whiteflies, Bemisia argentifolii, and Erwinia rhapontici.

Isomaltulose [alpha-D-glucopyranosyl-(1,6)-D-fructofuranose] and trehalulose [alpha-D-glucopyranosyl-(1,1)-D-fructofuranose] are commercially valuable sucrose-substitutes that are produced in several microorganisms by the palI gene product, a sucrose isomerase. Trehalulose also occurs in the silverleaf whitefly, Bemisia argentifoli, as the major carbohydrate in the insect's honeydew. To determine if the enzyme that synthesizes trehalulose in whiteflies was similar to the well-characterized sucrose isomerase from microbial sources, the properties of the enzymes from whiteflies and the bacterium, Erwinia rhapontici, were compared. Partial purification of both enzymes showed that the enzyme from whiteflies was a 116 kD membrane-associated polypeptide, in contrast to the enzyme from E. rhapontici, which was soluble and 66 kD. The enzyme from E. rhapontici converted sucrose to isomaltulose and trehalulose in a 5:1 ratio, whereas the enzyme from whiteflies produced only trehalulose. Unlike the E. rhapontici enzyme, the whitefly enzyme did not convert isomaltulose to trehalulose, but both enzymes catalyzed the transfer of fructose to trehalulose using sucrose as the glucosyl donor. The results indicate that trehalulose synthase from whiteflies is structurally and functionally distinct from the sucrose isomerases described in bacteria. The whitefly enzyme is the first reported case of an enzyme that converts sucrose to exclusively trehalulose.

Animals↗

PubMed1998

Purification and some properties of 2-hydroxychromene-2-carboxylate isomerase from naphthalenesulfonate-assimilating Pseudomonas sp. TA-2.

A 2-hydroxychromene-2-carboxylate isomerase was purified from a cell-free extract of naphthalenesulfonate-assimilating Pseudomonas sp. TA-2 to an electrophoretically homogeneous state by successive column chromatography on DEAE-cellulose, DEAE-Toyopearl 650M, Sephadex G-75, Hydroxyapatite, and Mono Q. The enzyme had a molecular mass of 25 and 27 kDa as estimated by SDS-PAGE and Superdex 200, respectively. Its N-terminal 30 amino acid sequence had high homology with the deduced amino acid sequences of the 2HC2CA isomerase of nahD (a gene of naphthalene metabolism), pahD (a gene of naphthalene and phenanthrene metabolism), and doxJ (a gene of dibenzothiophene metabolism). The enzymatic product was a trans isomer. The isomerase activity was inhibited in the presence of monoiodoacetate or Hg2+, but not by preincubation with monoiodoacetate or N-ethylmaleimide. GSH functioned as a cofactor and activated the enzyme at above 0.15 mM.

Amino Acid Sequence↗

PubMed1976

Growth on D-lyxose of a mutant strain of Escherichia coli K12 using a novel isomerase and enzymes related to D-xylase metabolism.

Escherichia coli K12 cannot grow on D-lyxose, but a mutant was isolated which can utilize D-lyxose as sole source of carbon and energy for growth. D-Lyxose is transported into the bacteria by the D-xylose permease. The mutant constitutively synthesizes a new isomerase which is not inducible in the parent strain under any of the conditions tested. This enzyme, whose native substrate appears to be D-mannose, fortuitously converts D-lyxose into D-xylulose. Its structural gene is located at around 85 min on the E. coli genetic map, away from other known isomerase genes. D-Xylulose is subsequently catabolized by the enzymes of the normal D-xylose metabolic pathway. D-Mannose isomerase was partially purified and some of its properties were examined.

Carbohydrate Epimerases↗

PubMed1993

Chlamydia trachomatis Mip-like protein has peptidyl-prolyl cis/trans isomerase activity that is inhibited by FK506 and rapamycin and is implicated in initiation of chlamydial infection.

The Mip-like protein of Chlamydia trachomatis has sequence similarity with both the Mip protein of Legionella pneumophila, a virulence factor necessary for optimal intracellular infection, and FK506-binding proteins (FKBPs) of both prokaryotic and eukaryotic origin. FKBPs contain a site for peptidyl-prolyl cis/trans isomerase activity, which is blocked upon binding of the drugs, FK506 or rapamycin. In this paper we report that the recombinant chlamydial Mip-like protein exhibits a peptidyl-prolyl cis/trans isomerase activity which is inhibited by either rapamycin or FK506. To assess the role of the Mip-like protein in chlamydial infection, rapamycin or FK506 (25 microM), were used in either treatment of chlamydial organisms prior to inoculation, or were present at different intervals through the infection. Pretreatment of organisms alone reduced infectivity for McCoy cells by 30%, with inhibition rising to 80% on more prolonged exposure from 0 to 8h and 8 to 16h post-inoculation and declining thereafter. When drug was present during the developmental cycle at intervals from 0 to 24h post-inoculation abnormal chlamydiae were induced in residual inclusions. The results suggest that inhibition of the isomerase of the Mip-like protein interferes with one or more early events in the infective process that determine productive intracellular infection.

Amino Acid Sequence↗

PubMed2004

X-ray structure of peptidyl-prolyl cis-trans isomerase A from Mycobacterium tuberculosis.

Peptidyl-prolyl cis-trans isomerases (EC 5.2.1.8) catalyse the interconversion of cis and trans peptide bonds and are therefore considered to be important for protein folding. They are also thought to participate in processes such as signalling, cell surface recognition, chaperoning and heat-shock response. Here we report the soluble expression of recombinant Mycobacterium tuberculosis peptidyl-prolyl cis-trans isomerase PpiA in Escherichia coli, together with an investigation of its structure and biochemical properties. The protein was shown to be active in a spectrophotometric assay, with an estimated kcat/Km of 2.0 x 10(6) m(-1).s(-1). The X-ray structure of PpiA was solved by molecular replacement, and refined to a resolution of 2.6 A with R and Rfree values of 21.3% and 22.9%, respectively. Comparisons to known structures show that the PpiA represents a slight variation on the peptidyl-prolyl cis-trans isomerase fold, previously not represented in the Protein Data Bank. Inspection of the active site suggests that specificity for substrates and cyclosporin A will be similar to that found for most other enzymes of this structural family. Comparison to the sequence of the second M. tuberculosis enzyme, PpiB, suggests that binding of peptide substrates as well as cyclosporin A may differ in that case.

Amino Acid Sequence↗

PubMed1979

Purification, Immobilization, and Some Properties of Glucose Isomerase from Streptomyces flavogriseus.

Glucose isomerase (EC 5.3.1.5) produced from Streptomyces flavogriseus was purified by fractionation with (NH(4))(2)SO(4) and chromatography on diethylaminoethyl (DEAE)-cellulose and DEAE-Sephadex A-50 columns. The purified enzyme was homogeneous as shown by ultracentrifugation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Benzyl DEAE-cellulose, triethylaminoethyl-cellulose, and DEAE-cellulose were effective in the immobilization of partially purified glucose isomerase. Several differences in properties were found between purified soluble enzyme, immobilized enzyme (DEAE-cellulose-glucose isomerase), and heat-treated whole cells. Glucose and xylose served as substrate for the enzyme. Whole cells had the highest K(m) values for glucose and xylose; the soluble enzyme had the lowest values. The optimum temperature for activity of the soluble and immobilized enzymes was 70 degrees C; that for whole cells was 75 degrees C. The pH optimum for the three enzyme preparations was 7.5. Magnesium ion or Co was required for enzyme activity; an addition effect resulted from the presence of both Mg and Co. The enzyme activity was inhibited by Hg, Ag, or Cu. The conversion ratio of the enzyme for isomerization was about 50%. The soluble and immobilized enzymes showed a greater heat stability than whole cells. The soluble enzyme was stable over a slightly wider pH (5.0 to 9.0) range than the immobilized enzyme and whole cells (pH 5.5 to 9.0). The molecular weight of the enzyme determined by the sedimentation equilibrium method was 171,000. A tetrameric structure for the enzyme was also indicated. After operating at 70 degrees C for 5 days, the remaining enzyme activity of the immobilized enzyme and whole cells, which were used for the continuous isomerization of glucose in a plug-flow type of column in the presence of Mg and Co, was 75 and 55%, respectively. Elimination of Co decreased operational stability.

Journal Article↗