Non-enzymatic glycation as the chain reaction between reducing sugars and free amino groups of proteins has been shown to correlate with physiological ageing and severity of diabetes. The process involves oxidative steps (glycoxidation). In this paper, the effect of D-fructose as a reactive sugar on aspartate aminotransferase (AST) as a model protein was monitored by measurements of the enzyme activity and formation of fluorescent advanced glycation end products (AGEs). Change in the AST activity was considered as a measure of the overall protein damage caused by glycation, and total AGEs and pentosidine represent, at least partly, the formation of glycoxidation products. Catalytic activity of AST in an incubation mixture containing D-fructose (50 mmol L(-1)), decreased compared to control values to 42% (p < 0.05) and to 11% (p < 0.05) on the 5th and on 21st day of incubation, respectively. In the presence of fructose, total fluorescent AGEs concentration was significantly higher since 5th day of incubation (110%, p < 0.05) and the fluorescent pentosidine concentration from 15th day of incubation (117%, p < 0.05) compared to control values, respectively. Catalytic activity of AST clearly and quantitatively demonstrated functional changes in the enzyme molecule caused by structural modifications initiated by fructose, while the evaluation of AGE formation and especially that of pentosidine by fluorescence measurement was less reliable.
- MeSH
- arginin analogy a deriváty biosyntéza MeSH
- aspartátaminotransferasy metabolismus MeSH
- fluorescenční spektrometrie MeSH
- fruktosa farmakologie MeSH
- katalýza MeSH
- lysin analogy a deriváty biosyntéza MeSH
- myokard enzymologie MeSH
- oxidace-redukce MeSH
- prasata MeSH
- produkty pokročilé glykace biosyntéza MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- arginin MeSH
- aspartátaminotransferasy MeSH
- fruktosa MeSH
- lysin MeSH
- pentosidine MeSH Prohlížeč
- produkty pokročilé glykace MeSH
Arcanobacterium haemolyticum was isolated from 8,641 throat swabs in 49 cases (0.56%), from patients aged 16 to 24 years only, twice more often from men than from women. The isolation was achieved on sheep blood agar supplemented with streak with Staphylococcus aureus strain producing beta-lysine. In all cases the presence of A. haemolyticum colonies was disclosed by the irregular periphery of haemolysis around the staphylococcal streak after the 48-hour incubation. The technique described should be used as a standard procedure for examining throat swabs.
- MeSH
- akutní nemoc MeSH
- bakteriologické techniky * MeSH
- Corynebacterium enzymologie izolace a purifikace MeSH
- dospělí MeSH
- faryngitida mikrobiologie MeSH
- farynx mikrobiologie MeSH
- fosfolipasa D biosyntéza MeSH
- hemolýza MeSH
- lidé MeSH
- lysin analogy a deriváty biosyntéza MeSH
- mladiství MeSH
- Staphylococcus aureus metabolismus MeSH
- tonzilitida mikrobiologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- beta-lysine MeSH Prohlížeč
- fosfolipasa D MeSH
- lysin MeSH
Genes of the threonine operon of Escherichia coli were used for the construction of a Brevibacterium flavum strain excreting threonine. Using the shuttle vector pCEM300 and a newly constructed shuttle vector pEC71 (7.1 kb, Kmr/Nmr), various plasmids carrying E. coli thr genes were prepared. Mutants resistant to the threonine analog 2-amino-3-hydroxyvaleric acid (AHV) were isolated after the ethyl methanesulfonate treatment of B. flavum carrying these recombinant plasmids. A mutant of B. flavum CCM 351 carrying the cloned genes thrA and thrB accumulated 12 g/L of threonine after 48 h of cultivation.
- MeSH
- bakteriální geny genetika MeSH
- Brevibacterium enzymologie genetika metabolismus MeSH
- Escherichia coli genetika MeSH
- exprese genu fyziologie MeSH
- fosfotransferasy s alkoholovou skupinou jako akceptorem metabolismus MeSH
- genetické vektory MeSH
- homoserindehydrogenasa metabolismus MeSH
- lysin biosyntéza MeSH
- operon MeSH
- plazmidy MeSH
- threonin biosyntéza genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fosfotransferasy s alkoholovou skupinou jako akceptorem MeSH
- homoserindehydrogenasa MeSH
- homoserine kinase MeSH Prohlížeč
- lysin MeSH
- threonin MeSH
Using mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine, a number of homoserine auxotrophs have been isolated from a glutamate-producing Arthrobacter globiformis excreting L-lysine in good amounts. For further improvement, mutants resistant to the lysine analog S-(2-aminoethyl)-L-cysteine have been isolated from homoserine auxotrophs. For the three potent mutants tested, White's medium was found to be the best. Glucose, ammonium nitrate and biotin were found to be optimum at 280 mmol/L, 40 mmol/L and 22 nmol/L, respectively. With optimal glucose, ammonium nitrate and biotin, the strain AECrVI yielded 36 g lysine per L in flask culture.
- MeSH
- antibiotická rezistence genetika MeSH
- Arthrobacter účinky léků genetika metabolismus MeSH
- biotin farmakologie MeSH
- cystein analogy a deriváty farmakologie MeSH
- druhová specificita MeSH
- dusík metabolismus MeSH
- glukosa metabolismus MeSH
- kultivační média MeSH
- lysin biosyntéza MeSH
- methylnitronitrosoguanidin MeSH
- mutace MeSH
- mutageneze MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biotin MeSH
- cystein MeSH
- dusík MeSH
- glukosa MeSH
- kultivační média MeSH
- lysin MeSH
- methylnitronitrosoguanidin MeSH
- S-2-aminoethyl cysteine MeSH Prohlížeč
By using dimethyl sulfoxide or Tween 80 (1 or 0.2%), the production of L-lysine was increased by 20-28 and 23-25%, respectively, in regulatory mutant strains of Corynebacterium glutamicum. The stimulation observed is supposed to be caused by influencing cellular surface structures.
- MeSH
- Corynebacterium účinky léků genetika metabolismus MeSH
- dimethylsulfoxid farmakologie MeSH
- lysin biosyntéza MeSH
- mutace MeSH
- polysorbáty farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- dimethylsulfoxid MeSH
- lysin MeSH
- polysorbáty MeSH
To improve the yield of lysine by the isolate, auxotrophic mutants were isolated. Among the mutants, only one auxotrophic mutant required vitamin B12. This mutant produced alpha-alanine. About 200 mutants resistant to the lysine analog S-(2-aminoethyl)-L-cysteine were isolated and some of them produced well above the wild type.
- MeSH
- alanin biosyntéza MeSH
- antibiotická rezistence genetika MeSH
- Arthrobacter genetika izolace a purifikace metabolismus MeSH
- bakteriologické techniky MeSH
- cystein analogy a deriváty farmakologie MeSH
- lysin biosyntéza MeSH
- methylnitronitrosoguanidin MeSH
- mutace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- alanin MeSH
- cystein MeSH
- lysin MeSH
- methylnitronitrosoguanidin MeSH
- S-2-aminoethyl cysteine MeSH Prohlížeč
Some Bacillus subtilis mutants with different levels of homoserine dehydrogenase were described. Strains that do not accumulate methionine have a high homoserine dehydrogenase activity. Low activity was detected in mutants where cell growth was completely inhibited by 0.7 mmol/L methionine. A low concentration of dimethyl sulfoxide had a stimulatory effect on lysine production by the methionine-sensitive mutant of Bacillus subtilis.
- MeSH
- Bacillus subtilis účinky léků genetika metabolismus MeSH
- cystein analogy a deriváty farmakologie MeSH
- dimethylsulfoxid farmakologie MeSH
- homoserindehydrogenasa metabolismus MeSH
- lysin biosyntéza MeSH
- mutace MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- cystein MeSH
- dimethylsulfoxid MeSH
- homoserindehydrogenasa MeSH
- lysin MeSH
- S-2-aminoethyl cysteine MeSH Prohlížeč
A mutant Corynebacterium sp. requiring threonine and cultivated for 3 d in a medium containing 15% sucrose, 8% corn-steep and 50 micrograms biotin per litre accumulated 14.5 g L-homoserine per litre. The possibility of fermenting the homoserine obtained for threonine and lysine production was investigated.
- MeSH
- Corynebacterium genetika metabolismus MeSH
- druhová specificita MeSH
- fermentace MeSH
- homoserin biosyntéza metabolismus MeSH
- kinetika MeSH
- kultivační média MeSH
- lysin biosyntéza MeSH
- mutace MeSH
- threonin biosyntéza MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- homoserin MeSH
- kultivační média MeSH
- lysin MeSH
- threonin MeSH
- MeSH
- biotin farmakologie MeSH
- Brevibacterium metabolismus MeSH
- fermentace * MeSH
- glukosa metabolismus MeSH
- lysin biosyntéza farmakologie MeSH
- threonin farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biotin MeSH
- glukosa MeSH
- lysin MeSH
- threonin MeSH
The production of L-lysine from DL-alpha-amino-epsilon-caprolactam (DL-ACL) by new strains producing L-alpha-amino-epsilon-caprolactamase and aminocaprolactam racemase is described. Optimal conditions for hydrolysis of L-ACL by Cryptococcus sp. and for racemization of ACL by cells of a strain isolated in nature and identified as Pseudomonas sp. were determined. Synthesis of L-alpha-amino-epsilon-caprolactamase is induced by DL-ACL or L-lysine with the same effectivity. A positive effect of phosphates (potassium salts) on reduction of the induction lag was detected, the synthesis of this enzyme was found to be repressed by glucose and some possibilities of the reversion of this repressive effect were demonstrated. Under conditions optimal for the production of both enzymes a quantitative theoretical conversion of 10% aqueous DL-ACL to L-lysine by a mixture of native cells in a mass ratio of 1 : 2 (producer of ACL-hydrolase to producer of ACL-racemase) occurred in 8 h at 40 degrees C and pH 8.0.
- MeSH
- amidohydrolasy metabolismus MeSH
- azepiny metabolismus MeSH
- Cryptococcus enzymologie MeSH
- fosfáty farmakologie MeSH
- glukosa farmakologie MeSH
- isomerasy aminokyselin metabolismus MeSH
- kaprolaktam metabolismus MeSH
- lysin biosyntéza MeSH
- Pseudomonas enzymologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- amidohydrolasy MeSH
- aminocaprolactam racemase MeSH Prohlížeč
- azepiny MeSH
- fosfáty MeSH
- glukosa MeSH
- isomerasy aminokyselin MeSH
- kaprolaktam MeSH
- L-alpha-amino-epsilon-caprolactamase MeSH Prohlížeč
- lysin MeSH
