Stable expression of mammalian beta 1,4-galactosyltransferase extends the N-glycosylation pathway in insect cells

An established lepidopteran insect cell line (Sf9) was cotransfected with expression plasmids encoding neomycin phosphotransferase and bovine beta 1,4-galactosyltransferase. Neomycin-resistant transformants were selected, assayed for beta 1,4-galactosyltransferase activity, and the transformant with the highest level of enzymatic activity was characterized. Southern blots indicated that this transformed Sf9 cell derivative contained multiple copies of the galactosyltransferase- encoding expression plasmid integrated at a single site in its genome. One-step growth curves showed that these cells supported normal levels of baculovirus replication. Baculovirus infection of the transformed cells stimulated beta 1,4-galactosyltransferase activity almost 5-fold by 12 h postinfection. This was followed by a gradual decline in activity, but the infected cells still had about as much activity as uninfected controls as late as 48 h after infection and they were able to produce a beta 1,4-galactosylated virion glycoprotein during infection. Infection of the transformed cells with a conventional recombinant baculovirus expression vector encoding human tissue plasminogen activator also resulted in the production of a galactosylated end-product. These results demonstrate that stable transformation can be used to add a functional mammalian glycosyltransferase to lepidopteran insect cells and extend their N- glycosylation pathway. Furthermore, stably-transformed insect cells can be used as modified hosts for conventional baculovirus expression vectors to produce foreign glycoproteins with "mammalianized" glycans which more closely resemble those produced by higher eucaryotes.      

Molecular docking analysis of bioactive compounds from Cissampelos pareira with PPAR gamma

We document the Molecular docking analysis of bioactive compounds from Cissampelos pareira with PPAR gamma for further consideration in drug discovery for T2DM.     

Microvascular membrane permeability in high surface tension pulmonary edema

Pulmonary edema was induced in dogs by an aerosol of detergent dioctyl sodium sulfosuccinate. The permeability of the pulmonary microvascular membrane was assessed by cannulating an afferent tracheobronchial lymphatic and comparing the lymph-to-plasma total protein concentration (CL/CP) during high lymph flows induced by increasing left atrial (LA) pressure after detergent aerosol. Base-line CL/CP of 0.69 +/- 0.02 fell to 0.55 +/- 0.03 with increased LA pressure alone. CL/CP fell to 0.47 +/- 0.02 when LA pressure was increased following detergent, 0.51 +/- 0.04 following an aerosol of the vehicle in which the detergent was dissolved, and 0.73 +/- 0.10 following intravenous alloxan. In additional animals protein concentration of the airway edema fluid was compared with that of plasma. The ration of protein concentration of airway fluid to plasma was 0.63 +/- 0.08 following detergent aerosol, 0.64 +/- 0.10 following increased LA pressure, and 0.94 +/- 0.09 following administration of alloxan. These data indicate no major increase in pulmonary microvascular permeability following detergent aerosol and support the concept that pulmonary edema is the consequence of reduced interstitial perimicrovascular hydrostatic pressure caused by increased alveolar surface tension.