Untitled

Abstract

The isolation of a new type of thrombin inhibitor, called triabin, from the saliva of the hematophagous bug Triatoma pallidipennis, has recently been described. In the in vitro platelet aggregation inhibition assay triabin has a similar potency as the thrombin inhibitor hirudin now in phase III clinical trials. However, in another in vitro assay using a low molecular weight substrate for thrombin, triabin does not inhibit thrombin completely even at 6 fold higher molar doses in comparison with hirudin. This means that triabin has a novel mode of action towards thrombin making triabin into an interesting candidate as a therapeutic agent. Recently it has been shown that a recombinant baculovirus can be efficiently used for the triabin production in insect cells and that the yields in adherent cultures of High Five™ cells (approx. 20 mg l-1) were about 7 fold higher than in adherent cultures of Sf9 cells (approx. 3 mg l- 1). To optimize the triabin yield from the baculovirus/insect cell expression system, experiments were performed with suspension adapted cultures of High Five™ cells to investigate the effects of the state of the host cell, of the multiplicity of infection, of the cell density at the time of infection and of supplementation of the medium with nutrients and oxygen. Triabin yields of up to 200 mg l-1, as determined by an activity assay, could finally be obtained here.

Characterization of the Glycan Structures of GlycoproteinGA733‐Fc Expressed in a Baculovirus‐Insect Cell System

“…However, in the insect cells, the glycosylation pattern of recombinant glycoproteins has not been characterized under various conditions such as cell type, postinfection (PI) time, and sampling location. The predominantly used cell lines for the baculovirus expression system include the Spodoptera frugiperda ‐derived cell line “Sf9” and the Trichoplusia ni ‐derived cell line “High Five.” The High Five cell line is used more often than the Sf9 cell line because it replicates rapidly and secretes recombinant glycoproteins at a higher rate than the Sf9 cell line . Thus, the harvesting time after the virus infects the cells (PI time) directly and affects the recombinant protein expression as well as glycosylation.…”

Targeted Metabolic Analysis and MFA of Insect Cells Expressing Influenza HA-VLP

“…This behavior allows one to complement the mitochondria redox potential and facilitate the supply of O 2 for aerobic respiration, generating enough energy for cellular growth [19,24,37]. Upon infection, cells changed their metabolism considerably; cells started to use almost exclusively glucose as a carbon source and decreased the use of amino acids as a source of TCA cycle intermediates, as previously reported [38][39][40]. Deviation of amino acid consumption from the energy route towards viral production and VLP protein expression has been suggested before [41].…”

Statistical Determination of Optimal Baculovirus Infection Condition for Recombinant Protein Production in Drosophila S2 Cells

“…These experimental variables are generally regarded as important conditions for expression of heterologous protein in baculovirus/insect cell culture [26,[30][31][32]. MOI is a critical variable for baculovirus-mediated protein expression in nonpermissive cell lines such as S2 cells because infected baculovirus cannot be replicated inside the cells.…”