Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As is shown expression homologous (dihydroxyacetone kinase) and heterologous (HBsAg, beta-galactosidase) genes in methylotrophic yeasts Hansenula polymorpha DL1 negatively affects on the growth parameters of a host strain. The reducing of specific growth rate (mu max) and yield of biomass per the unit of a consumed substrate (Yx/s) were found in all recombinant strains grown on methanol. Overproduction of dihydroxyacetone kinase and beta-galactosidase in recombinant H. polymorpha was accompanied by two-fold increasing of the activity of alcohol oxidase, which is the first enzyme of methanol oxidation. Otherwise, the activity of formaldehyde dehydrogenase two-fold decreased in the recombinant strain overproducing HBsAg compared with the host strain. It is suggested that the over-synthesis of foreign proteins requiring an additional energetic and metabolic expenses might reduce the growth parameters and the activities of some enzymes of methanol metabolism in recombinant methylotrophic yeast H. polymorpha.
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PMID:[Effect of over-synthesis of cloned gene products on methanol metabolism in the recombinant methylotrophic yeast Hansenula polymorpha]. 799 Jul 33

Changes in the activities of key enzymes responsible for utilization of methanol by recombinant strains of methylotrophic yeasts H. polymorpha R22-2B and H. polymorpha LAC-56 grown in a chemostat are described. The strain R22-2B displaying a high activity of dioxyacetone kinase had also a high activity of formaldehyde dehydrogenase, which increased the rate of dissimilation of formaldehyde. There was a decrease in ATP concentration in the strain LAC-56 oversynthesizing beta-galactosidase from Escherichia coli; this effect decreased the rate of assimilation of formaldehyde.
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PMID:[Biochemical response of recombinant Hansenula polymorpha strains to oversynthesis of homologous dioxyacetone kinase and bacterial beta-galactosidase]. 863 40

Whole-mount detection methods are quick, inexpensive and offer the possibility of studying the temporal and spatial patterns of gene expression in a morphological context. These methods have been used widely to detect messenger RNAs and to measure enzymatic activity of reporter genes, such as beta-galactosidase or beta-glucuronidase. Taking advantage of the fact that NADH generated during the oxidation of formaldehyde by class III alcohol dehydrogenase can reduce the compound nitroblue tetrazolium to form a blue precipitate, we have developed a new method to detect class III alcohol dehydrogenase activity in situ in whole Arabidopsis plants. This reaction has been used earlier for in situ electrophoresis detection and for histochemical analysis in animal tissue sections. With a few modifications, it can be used in whole Arabidopsis plants or excised plant tissues to allow a rapid analysis of class III ADH activity during development or in response to elicitors. The method might be extended to other dehydrogenases by using specific substrates.
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PMID:Histochemical assay to detect class III ADH activity in situ in Arabidopsis seedlings. 1551 10

Continuous, single-step, state-of-the-art preparative separations of enzymes from microorganism crude extracts by free-flow zone electrophoresis are presented. In the first example, the enzymes formate dehydrogenase, formaldehyde dehydrogenase, and methanol oxidase were continuously separated from Candida boidinii crude extract. Yields of 85% to 95% and purification factors between 3 and 7 were obtained along with a simultaneous separation of the finer cell debris from the enzymes. Using multiple injections of sample, a throughput of 46.2 mg protein/h was recorded. In the second example, a fivefold purification of beta-galactosidase from Escherichia coli was achieved along with complete, simultaneous cell debris separation from the enzyme. The yield of the enzyme was greater than 90%. The preparative free-flow zone electrophoresis experiments were run continuously for a period of 12 h and the separations were found to be stable; i.e., the enzymes and the cell debris eluted at their respective fraction numbers during the entire period. In both examples, choice of the type of buffer played a critical role and had to be investigated and optimized experimentally. Scale-up aspects of the separations are also discussed. Recently, by comparison of free-flow zone electrophoresis with ion-exchange chromatography, we have presented evidence that free-flow electrophoresis separations are governed by net surface charge (S. Nath et al., Biotechnol. Bioeng. 1993, 42: 829-835). Here, we offer further confirmation of this evidence by comparison of preparative free-flow zone electrophoresis experiments at various pHs on a mixture of two model proteins with analytical electrophoretic titration curves of the proteins. We are thus in a position to predict separations in free-flow zone electrophoresis. (c) 1996 John Wiley & Sons, Inc.
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PMID:Separation of enzymes from microorganism crude extracts by free-flow zone electrophoresis. 1862 83