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)

To identify membrane components of CER cells interacting with vesicular stomatitis virus (VSV) during fusion at acidic pH (fusion from without, FFWO) two different approaches have been used, i.e. (i) treating the whole cells with enzymes and (ii) testing the ability of isolated membrane molecules to interfere with FFWO. Phospholipase A2 and C digestion of cells greatly reduced syncytia formation, pointing towards the involvement of lipid structures as target sites for VSV. Cell susceptibility to FFWO was also reduced after neuraminidase, beta-galactosidase or periodate treatment, suggesting that carbohydrate residues may participate in a complex receptor structure required for virus fusion. When membrane molecules were examined separately for their ability to inhibit viral FFWO, phosphatidylserine, phosphatidylinositol, sphingomyelin, cholesterol and GM3 ganglioside were found to be active, confirming the role of membrane lipid moiety in the cell surface structures involved in the early phases of VSV infection.
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PMID:Role of membrane phospholipids and glycolipids in cell-to-cell fusion by VSV. 166 Jul 97

Respiration rates in Spodoptera frugiperda (Sf-9) cell bioreactor cultures were successfully measured on-line using two methods: The O(2) uptake rate (OUR) was determined using gas phase pO(2) values imposed by a dissolved oxygen controller and the CO(2) evolution rate (CER) was measured using an infrared detector. The measurement methods were accurate, reliable, and relatively inexpensive. The CER was routinely determined in bioreactor cultures used for the production of several recombinant proteins. Simple linear relationships between viable cell densities and both OUR and CER in exponentially growing cultures were used to predict viable cell density. Respiration measurements were also used to follow the progress of baculoviral infections in Sf-9 cultures. Infection led to increases in volumetric and per-cell respiration rates. The relationships between respiration and several other culture parameters, including viable cell density, cell protein, cell volume, glucose consumption, lactate production, viral titer, and recombinant beta-galactosidase accumulation, were examined. The extent of the increase in CER following infection and the time postinfection at which maximum CER was attained were negatively correlated with the multiplicity of infection (MOI) at multiplicities below the level required to infect all the cells in a culture. Delays in the respiration peak related to the MOI employed were correlated with delays in the peak in recombinant protein accumulation. DO levels in the range 5-100% did not exert any major effects on viable cell densities, CER, or product titer in cultures infected with a baculovirus expressing recombinant beta-galactosidase.
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PMID:On-line monitoring of respiration in recombinant-baculovirus infected and uninfected insect cell bioreactor cultures. 1862 97