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)

Modified vaccinia Ankara (MVA), a highly attenuated vaccinia virus strain that has been safety tested in humans, was evaluated for use as an expression vector. MVA has multiple genomic deletions and is severely host cell restricted: it grows well in avian cells but is unable to multiply in human and most other mammalian cells tested. Nevertheless, we found that replication of viral DNA appeared normal and that both early and late viral proteins were synthesized in human cells. Proteolytic processing of viral structural proteins was inhibited, however, and only immature virus particles were detected by electron microscopy. We constructed an insertion plasmid with the Escherichia coli lacZ gene under the control of the vaccinia virus late promoter P11, flanked by sequences of MVA DNA, to allow homologous recombination at the site of a naturally occurring 3500-base-pair deletion within the MVA genome. MVA recombinants were isolated and propagated in permissive avian cells and shown to express the enzyme beta-galactosidase upon infection of nonpermissive human cells. The amount of enzyme made was similar to that produced by a recombinant of vaccinia virus strain Western Reserve, which also had the lacZ gene under control of the P11 promoter, but multiplied to high titers. Since recombinant gene expression is unimpaired in nonpermissive human cells, MVA may serve as a highly efficient and exceptionally safe vector.
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PMID:Nonreplicating vaccinia vector efficiently expresses recombinant genes. 143 87

We constructed a plasmid that contains a small piece of DNA with two vaccinia promoters running in opposite directions--a promoter from a late gene encoding an 11 K polypeptide (P11) and a promoter from an early gene encoding 25K (P25). These promoters were isolated from the Tian Tan strain of vaccinia virus and were flanked by the thymidine kinase (TK) sequence of the same virus. Genes encoding the hepatitis B virus surface antigen (HBsAg) and the Escherichia coli beta-galactosidase (LacZ) were inserted downstream of the 11 K and 25 K promoters respectively so that coexpression plasmids were constructed. Recombinant vaccinia viruses were selected directly by picking blue plaques formed under overlaying agarose medium containing X-gal. HBsAg was expressed to high level by these recombinant viruses. These recombinant viruses showed reduced virulence on rabbit skin and induced anti-HBs after intradermal inoculation of rabbits.
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PMID:Selection of recombinant vaccinia viruses (Tian Tan strain) expressing hepatitis B virus surface antigen by using beta-galactosidase as a marker. 211 Nov 42

Seven antisera raised against 11 alpha-hydroxyprogesterone 11-hemisuccinate (P11-HS) were used in microtitre plate enzymeimmunoassays (EIAs) for progesterone to identify improvements in sensitivity achievable by using various heterologous labels. EIAs using beta-galactosidase linked to P11-HS, 11 alpha-hydroxyprogesterone 11-hemimaleate (P11-HM), 11 alpha-hydroxyprogesterone 11-glucuronide (P11-Glu) or progesterone 3-(o-carboxymethyl) oxime (P3-CMO) were compared. Loss of sensitivity through bridge recognition was least evident using the P11-Glu derivative. The same seven antisera were used to evaluate assay sensitivity using beta-galactosidase, alkaline phosphatase, penicillinase and peroxidase linked to P11-HS or P11-Glu as label. Consistent improvements were achieved with the heterologous assays in the order penicillinase greater than alkaline phosphatase/peroxidase greater than beta-galactosidase: with penicillinase, sensitivity generally exceeded that of RIA. These data provide evidence for the general efficacy of the combination 11 alpha-hemisuccinate (immunogen bridge) and 11 alpha-glucuronide (label bridge) in reducing bridge recognition. EIA performed at 4 degrees C provided greater sensitivity than at ambient temperature (21 degrees C) or 40 degrees C, however, ambient temperature incubation provided a practical compromise. Equilibrium was not achieved under any of the conditions investigated.
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PMID:The influence of heterology, enzyme label and assay conditions on the sensitivity of microtitre plate enzymeimmunoassays for progesterone in milk. 255 Jul 5

In a search for means to deliver exogenous gene(s) into human dendritic cells (DCs) from the perspective of tumor-specific vaccination, we have evaluated two recombinant viruses, both of which carry a reporter gene which is namely a modified vaccinia virus Ankara (MVA) and an adenovirus, as possible expression vectors. The recombinant MVA-P11 LZ vector carries the Escherichia coli lacZ gene coding for the enzyme beta-galactosidase, and the recombinant Ad-MFG-AP vector carries a modified membrane-exposed alkaline phosphatase (AP) gene. DCs were generated ex vivo in the presence of tumor necrosis factor-alpha, granulocyte macrophage colony-stimulating factor, stem cell factor, and flk-2/flt-3 ligand taken from CD34+ hematopoietic progenitors that were mobilized into the peripheral blood of cancer patients treated with high-dose cyclophosphamide and filgrastim. The target cells used for gene delivery were either CD34+ cells that had been subsequently induced to differentiate into mature DCs or DCs transduced after ex vivo generation from CD34+ cells. The results showed that: (a) infection of CD34+ cell derived-DCs (mature DCs) with either viral vector resulted in the efficient synthesis of recombinant protein, and (b) CD34+ cells were permissive for the expression of the recombinant reporter gene after infection with Ad-MFG-AP but not after infection with MVA-P11 LZ. In conclusion, these results suggest that vaccinia and adenovirus vectors are candidate to act as vehicles in genetically engineering human DCs.
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PMID:Gene transfer into human dendritic antigen-presenting cells by vaccinia virus and adenovirus vectors. 991 89

Because of the limited analysis of fowl poxvirus (FPV) promoters, expression of foreign proteins by recombinant FPV has usually been directed by heterologous vaccinia virus or synthetic poxvirus promoters. Thus, the impact of completely homologous recombinant virus vaccines has yet to be realized by the poultry industry. In an effort to increase the availability of such transcriptional regulatory elements, the modulation of gene expression by six previously uncharacterized FPV late promoters was examined. To simplify this comparison, each promoter region was separately coupled to the same reporter gene (lacZ) in individual plasmid constructs, and their activities in transfected, virus-infected cells were monitored. In each of the four selected unidirectional transcriptional regulatory elements as well as a 30-base pair representative of the bidirectional promoter region, the predicted temporal specificity of expressing at late stages of virus replicative cycle was verified. Stable lacZ gene transcripts arising from each plasmid varied less than threefold in quantity, whereas the amounts of beta-galactosidase product ranged within a 130-fold interval. Only the promoter that naturally regulates expression of the A type inclusion body protein gene directed production of beta-galactosidase at a level comparable with that associated with the strong vaccinia virus P11 promoter. Because one of the remaining unidirectional transcriptional regulatory elements, P174, was only 2.4-fold less efficient, both of these promoters, P174 and P190, should be satisfactory for directing the expression of poultry pathogen genes inserted into the genomes of FPV recombinant vaccines.
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PMID:A consideration of previously uncharacterized fowl poxvirus unidirectional and bidirectional late promoters for inclusion in homologous recombinant vaccines. 1288 88

In this communication, we describe the isolation of a Lactobacillus delbrueckii subsp. bulgaricus 92063 mutant strain named pH-P11, which differed from the parent strain by low proteolytic activity and altered regulation of expression of lacZ in the presence of glucose or lactose. In the presence of lactose, beta-galactosidase activity was approximately twice as high in pH-P11 than in the wild type. pH-P11 exhibited protosymbiosis together with Streptococcus thermophilus. Yoghurt produced with pH-P11 was characterized by low acidity and little post-acidification during storage. The organoleptic properties (absence of bitterness and other off-flavors, weak sourness, and clear yoghurt taste) were those of a typical "yoghurt mild". This mild flavor was achieved at rather high cell counts of lactobacilli even at the end of shelf-life. High cell counts in conjunction with high beta-galactosidase activity make pH-P11 an interesting strain for application in yoghurt especially designed for consumers with lactose malabsorption. In contrast to "yoghurt mild", which is predominantly produced with Lactobacillus acidophilus together with Streptococcus thermophilus, the product obtained by fermentation with pH-P11 and Streptococcus thermophilus concurs with international standards for yoghurt. During frequent sub-culturing, strain pH-P11, which is supposed to differ from the wild type by one or a few so-far-not-characterized mutations, showed sufficient stability for application in industrial production.
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PMID:Production of yoghurt with mild taste by a Lactobacillus delbrueckii subsp. bulgaricus mutant with altered proteolytic properties. 1726 Mar 32

Primary cultures of human mammary epithelial cells underwent significant morphological and functional changes during the aging process between passage 12 (P12) and passage 16 (P16). Concomitant with a progressive and significant expression of senescence-associated beta-galactosidase as aging marker, the cells restructured their attachment, increased in size and ceased to divide. Young HMEC until P11 demonstrated a nearly 100% expression of distinct adhesion molecules such as CD24, integrin beta1 (CD29) and CD44 similar to the human mammary tumor cell line MCF-7. In parallel with the aging-associated alterations of the cell adhesion, expression of CD24 and CD44 dropped in senescent P16 HMECs. However, levels of CD29 remained unchanged during the aging process. The tumor-associated Muc-1 (CD227), which was expressed to about 100% in the tumorigenic MCF-7 cells, was detectable in 51% of young HMEC in P11 and declined to 37% in aged HMEC in P16. In association with the remodeling of cell shape, expression levels of distinct matrix metalloproteinases including MMP-7 markedly decreased in aging HMEC. In contrast, MMP-1, MMP-2 and MMP-9 remained unchanged indicating a possible functional role of MMP-7 during the HMEC aging process. Indeed, down-modulation of MMP-7 by RNAi revealed a significantly elevated G(2)/M cell cycle arrest and a 2- to 3-fold enhanced senescence-associated beta-galactosidase expression as compared to control siRNA transfectants and control HMEC, respectively. Together, these findings suggested that decreasing MMP-7 expression contributes to accelerated aging of human mammary epithelial cells.
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PMID:MMP-7 is involved in the aging of primary human mammary epithelial cells (HMEC). 1820 46