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

The 70% ammonium sulfate-soluble fraction of the cyst fluid of Taenia hydatigena (designated ThFAS) was previously shown to have potential as an immunodiagnostic reagent for bovine cysticercosis. Western blot analysis indicated that the specific reactivity with antibodies in sera of T. saginata-infected cattle was associated with a 10 kDa component. Rabbit antiserum to ThFAS identified a homologous antigenic protein from the cestode Taenia crassiceps. Consequently, a cDNA expression library was constructed in lambda gt11 using poly A mRNA purified from T. crassiceps metacestodes and screened with rabbit antiserum to ThFAS. One strongly reactive clone (designated lambda TCA-2) produced a 123 kDa beta-galactosidase fusion protein which reacted in Western blot with sera from calves experimentally-infected with T. saginata and did not react with sera from uninfected calves or from cattle infected with Fasciola hepatica or with common gastrointestinal cattle parasites.
 ...
PMID:A recombinant immunodiagnostic antigen for bovine cysticercosis. 182 2

A method was developed for determining the specific activity of bacterial beta-galactosidase (EC 3.2.1.23) during growth of Streptococcus thermophilus and Lactobacillus bulgaricus in skim milk. Individual and mixed strain cultures of S. thermophilus (St 3642, St14485) and L. bulgaricus (Lb11842, Lb880) were examined for growth (OD at 600 nm and viable cell counts), acid production, and beta-galactosidase activity (expressed as a function of recoverable TCA-precipitable cellular protein). Cultures were inoculated into 10% skim milk (2% inoculum) and incubated at 40 degrees C for 12 h. Aliquots were removed at 2-h intervals and diluted with ice cold EDTA, pH 12. The EDTA chelates calcium and solubilizes milk protein, allowing separation of the bacteria by centrifugation. Cells were then washed twice with 20 mM phosphate buffer and disrupted by sonication. Cell debris and intact cells were removed by centrifugation and the cell-free extract evaluated for beta-galactosidase activity using o-nitrophenyl-beta-D-galactopyranoside as substrate. Specific activities ranged from 0 to 6 units/mg protein. This simple and reproducible method is applicable for enzyme assays and measurement of cellular components where contamination by milk proteins is a potential problem.
 ...
PMID:A method for determining beta-galactosidase activity of yogurt cultures in skim milk. 249 15

Protein antigens from 4-wk worms were metabolically radiolabelled with [3H]leucine or [35S]methionine. Three freeze-thaw cycles released a large proportion (50% to 60%) of the TCA-precipitable radioactivity from the worms. Immune serum from twice-infected Fischer rats (F-2x), which was shown to confer resistance in a passive immunization assay, and immune serum from twice-infected Wistar Furth rats (W-2x), which does not confer resistance, were used for analyzing antigens in this worm fraction. Antibodies in these antisera differed in their titers to the freeze-thaw released antigens (W-2x greater than F-2x) and in their relative affinities for these antigens (F-2x greater than W-2x). Gradient slab gel electrophoresis of immunoprecipitates of radiolabelled antigens under denaturing conditions revealed many components, which could be categorized into two main types: unique antigens, recognized only by F-2x antibodies, and nonunique antigens, recognized by both F-2x and W-2x antibodies. The potential relevance of these antigens in resistance was further examined by antibody absorption experiments in which 4-wk worms were used as an immunoabsorbent to remove 90% to 95% of the immunoprecipitating activity and 65% to 70% (p less than 0.005) of the capacity to confer resistance in a passive immunization assay. It was concluded that loss of both anti-schistosome activities was specific since antigen released by worms during absorption could account for only 16% of the reduction in antigen-binding capacity and the titer of antibodies directed against beta-galactosidase did not significantly change during absorption. Antigens recognized uniquely by F-2x antibodies are therefore candidates for immunization studies examining induction of resistance against Schistosoma mansoni.
 ...
PMID:Immunoprecipitation analysis of radiolabelled protein antigens biosynthesized in vitro by S. mansoni. I. Identification of antigens uniquely recognized by protective antibodies. 396 70

Pyridoxineless mutants of Escherichia coli B stopped incorporation of nucleosides into trichloroacetic acid-insoluble material about 40 to 60 min after pyridoxine starvation was initiated, whereas incorporation of amino acids (measured the same way) slowed but did not stop for several hours. Both these incorporations and cell density were increased most effectively by the presence of either threonine or isoleucine. Arginine, glutamate, histidine, methionine, tryptophan, and tyrosine also caused significant but less dramatic increases. Inducibility of beta-galactosidase continued beyond the point where nucleic acids appeared to stop their synthesis, suggesting that messenger ribonucleic acid synthesis continued beyond ribosomal ribonucleic acid synthesis. This inducibility was also increased by isoleucine and threonine. The overall results suggest that the threonine-isoleucine biosynthetic pathway is the most sensitive to starvation for pyridoxine.
 ...
PMID:Isoleucine and threonine can prolong protein and ribonucleic acid synthesis in pyridoxine-starved mutants of Escherichia coli B. 456 72

Protein import across both mitochondrial membranes is mediated by the cooperation of two distinct protein transport systems, one in the outer and the other in the inner membrane. Previously we described a 45 kDa yeast mitochondrial inner membrane protein (ISP45) that can be cross-linked to a partially translocated precursor protein (Scherer et al., 1992). We have now purified ISP45 to homogeneity and identified it as the product of the nuclear MPI1 gene. Identity of ISP45 with the MPI1 gene product was shown by microsequencing of three tryptic ISP45 peptides and by demonstrating that an antibody against an Mpi1p-beta-galactosidase fusion protein specifically recognizes ISP45. Antibodies monospecific for ISP45 inhibited protein import into right-side-out mitochondrial inner membrane vesicles, but not into intact mitochondria. On solubilizing mitochondria, ISP45 was rapidly converted to a 40 kDa proteolytic fragment unless mitochondria were first denatured with trichloroacetic acid. The combined genetic and biochemical evidence identifies ISP45/Mpi1p as a component of the protein import system of the yeast mitochondrial inner membrane.
 ...
PMID:Protein import into yeast mitochondria: the inner membrane import site protein ISP45 is the MPI1 gene product. 834 45

Microsomal membranes from growing tissue of pea (Pisum sativum L.) epicotyls were incubated with the substrate UDP-[14C]galactose (Gal) with or without tamarind seed xyloglucan (XG) as a potential galactosyl acceptor. Added tamarind seed XG enhanced incorporation of [14C]Gal into high-molecular-weight products (eluted from columns of Sepharose CL-6B in the void volume) that were trichloroacetic acid-soluble but insoluble in 67% ethanol. These products were hydrolyzed by cellulase to fragments comparable in size to XG subunit oligosaccharides. XG-dependent galactosyltransferase activity could be solubilized, along with XG fucosyltransferase, by the detergent 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate. When this enzyme was incubated with tamarind (Tamarindus indica L.) seed XG or nasturtium (Tropaeolum majus L.) seed XG that had been partially degalactosylated with an XG-specific beta-galactosidase, the rates of Gal transfer increased and fucose transfer decreased compared with controls with native XG. The reaction products were hydrolyzed by cellulase to 14C fragments that were analyzed by gel-filtration and high-performance liquid chromatography fractionation with pulsed amperometric detection. The major components were XG subunits, namely one of the two possible monogalactosyl octasaccharides (-XXLG-) and digalactosyl nonasaccharide (-XLLG-), whether the predominant octasaccharide in the acceptor was XXLG (as in tamarind seed XG) or XLXG (as in nasturtium seed XG). It is concluded that the first xylosylglucose from the reducing end of the subunits was the Gal acceptor locus preferred by the solubilized pea transferase. These observations are incorporated into a model for the biosynthesis of cell wall XGs.
 ...
PMID:Xyloglucan galactosyl- and fucosyltransferase activities from pea epicotyl microsomes. 915 50

This report contains a partial characterization of the epitope recognized by monoclonal antibody (MAb) ES78 produced against excretory-secretory (ES) antigens of Fasciola hepatica. ES78 is currently used for the detection of ES antigens in serum and stool samples of cattle and humans with fasciolosis, using a highly sensitive and specific sandwich enzyme-linked immunosorbent assay (ELISA). The epitope was characterized by periodate oxidation, alkaline borohydride reduction, trichloroacetic acid precipitation, beta-mercaptoethanol treatment, and enzymatic proteolysis. These results, together with those of the 2-site ELISA, lectin immunoassays, and beta-galactosidase digestion, showed that MAb ES78 reacts with a partly protein/partly carbohydrate antigenic determinant that is found on several ES molecules of adult specimens of F. hepatica and contains at least 1 disulfide bond and beta-galactose probably as galactose-beta(1-3)-N-acetylgalactosamine disaccharide.
 ...
PMID:Partial characterization of the epitope on excretory-secretory products of Fasciola hepatica recognized by monoclonal antibody ES78. 948 38

Neale, S. (Department of Botany, University College, London, England), and H. Tristram. Effect of O-methyl-dl-threonine and O-methyl-dl-serine on growth and protein synthesis in Escherichia coli. J. Bacteriol. 86:1241-1250. 1963.-Addition of either O-methyl-dl-threonine or O-methyl-dl-serine to exponentially growing cultures of Escherichia coli resulted in "linear" increases in optical density. The total cell count, however, remained constant, the increase in optical density being accompanied by a marked increase in cell length. In the presence of O-methyl-dl-serine, a phase of "linear" growth was followed by exponential growth, which was maintained during a second passage through analogue-containing medium but not after a subsequent passage through normal medium, suggesting phenotypic adaptation to the analogue. The differential rate of incorporation of amino acids into trichloroacetic acid-insoluble material was unaffected by growth in the presence of either O-methyl-dl-threonine or O-methyl-dl-serine. Neither analogue was incorporated into E. coli protein. The effect of the analogues on the production of alkaline phosphatase and beta-galactosidase was examined. The precise point and mode of action of the analogues have not been determined, but available evidence suggests that the growth-inhibitory effects of both substances are due to interference with the biosynthesis of threonine and methionine.
 ...
PMID:EFFECT OF O-METHYL-DL-THREONINE AND O-METHYL-DL-SERINE ON GROWTH AND PROTEIN SYNTHESIS IN ESCHERICHIA COLI. 1408 96

Escherichia coli is one of the most widely used hosts for the production of recombinant proteins, among other reasons because its genetics are far better characterized than those of any other microorganism. To improve the understanding of recombinant protein synthesis in E. coli, the production of a model recombinant protein, beta-galactosidase, was studied in response to the constitutive overexpression of the anaplerotic reaction afforded by PEP carboxylase. To this end, an IPTG wash-in experiment was performed starting from a well-defined steady-state condition for both the wild-type E. coli and a mutant with a defective acetate pathway and a constitutively overexpressed ppc. In order to compare the dynamics of the fluxes over time during the wash-in experiment, a method referred to as transient metabolic flux analysis, which is based on steady-state metabolic flux analysis, was used. This allowed us to track the intracellular changes/fluxes in both strains. It was observed that the flux towards fermentation products was 3.6 times lower in the ppc overexpression mutant compared to the wild-type E. coli. In the former on the other hand, the PPC flux is in general higher. In addition, the flux towards beta-galactosidase was higher (12.4 times), resulting in five times more protein activity. These results indicate that by constitutively overexpressing the anaplerotic ppc gene in E. coli, the TCA cycle intermediates are increasingly replenished. The additional supply of these protein precursors has a positive result on recombinant protein production.
 ...
PMID:Transient metabolic modeling of Escherichia coli MG1655 and MG1655 DeltaackA-pta, DeltapoxB Deltapppc ppc-p37 for recombinant beta-galactosidase production. 2044 May 35

To investigate the molecular basis of multiple-allele-inherited male sterility in Chinese cabbage (Brassica campestris L. ssp. pekinensis), we performed differential proteomic analysis using iTRAQ to identify differentially abundant proteins between fertile and sterile flower buds from the genetic male sterile line 'AB01'. We identified 5932 high-confidence proteins; 1494 were differentially abundant between the two samples, including 749 up- and 745 down-regulated proteins. The up- and down-regulated proteins that could be essential for anther development and male sterility in sterile buds were mainly involved in (1) carbohydrate and energy metabolism (pyruvate dehydrogenase, glycolysis/gluconeogenesis, TCA cycle, starch and sucrose metabolism), (2) pollen wall synthesis and regulation (pectinesterase, polygalacturonase, pectate lyase, beta-galactosidase, glycosyl hydrolase), (3) protein synthesis and degradation (proteasome subunits, ribosome proteins, ABC transporters, RNA transport, protein processing in endoplasmic reticulum), (4) flavonoid biosynthesis, and (5) plant hormone signal transduction. We identified 10 genes/proteins that were both up-regulated and 122 that were both down-regulated in a conjoint analysis. Multiple reaction monitoring and qRT-PCR validation showed that the iTRAQ results were accurate and reliable. These findings will provide valuable information on proteins involved in anther development, and will contribute to the understanding of the molecular mechanism(s) that underlie male sterility in Chinese cabbage. BIOLOGICAL SIGNIFICANCE: Chinese cabbage is an allogamous plant with bisexual flowers that displays significant heterosis. The application of male sterile lines is a very efficient way to produce hybrid seeds, which can generate stronger plants that develop more rapidly and produce higher yield. However, the molecular mechanism(s) underlying multiple-allele-inherited male sterility in Chinese cabbage is unknown. In this study, we used a quantitative proteomic approach (iTRAQ) to identify DAPs between fertile and sterile buds of the GMS line 'AB01'. Subsequently, we also performed conjoined analysis of the iTRAQ results and our previously reported transcriptomics results. The aim of this research was to obtain the key DAPs and to identify the significantly enriched pathways involved in anther development and male sterility. These results may provide new insights into the molecular mechanism(s) underlying multiple-allele-inherited male sterility in Chinese cabbage.
 ...
PMID:iTRAQ-based proteomic analysis of fertile and sterile flower buds from a genetic male sterile line 'AB01' in Chinese cabbage (Brassica campestris L. ssp. pekinensis). 3114 48


1