Metalloendopeptidases EC 3.4.24.15 and EC 3.4.24.16: potential roles in vascular physiology

The zinc metalloendopeptidases EC 3.4.24.15 (EP24.15) and EC 3.4.24.16 (EP 24.16) are closely relatedubiquitous enzymes, which have well-defined in vitroactivities in generation and degradation of a range ofspecific peptide targets. Despite this, little is knownregarding their roles in whole animal physiology. One of thepeptides degraded by these enzymes in vitro isbradykinin, a mediator with potent effects on the vasculatureat both systemic and local levels. This review summarises thework that has examined the role of EP 24.15/24.16 inregulation of the vascular effects of bradykinin invivo. This work was made possible by the development of aspecific stable inhibitor of these enzymes, JA-2. Use of thisinhibitor has shown that EP 24.15/24.16 are capable ofregulating responses induced by exogenous bradykinin. Thiseffect was observed at a systemic level with an increase inthe hypotensive effect of intravenous bradykinin. Further workis required to determine whether these enzymes also regulatebradykinin produced endogenously.     

In-vitro synthesis of a low molecular weight lipid-soluble luteotrophic factor by conceptuses of cows at day 13-18 of pregnancy

Two culture systems for maintenance of Day 13-18 conceptus tissue were developed. Harvested culture media were assayed for luteotrophic activity by determining their ability to stimulate progesterone synthesis by dispersed bovine luteal cells. Significant luteotrophic activity was found in 80% of the 31 tissue culture media studied. A series of experiments carried out to determine the nature of the luteotrophic activity indicate that it is a small (Mr less than 10,000), heat-labile, lipid-soluble substance that is adsorbed by dextran-coated charcoal. The nature and activity of this factor, together with its synthesis by the early bovine conceptus, suggest that it may have a significant role in stimulating progesterone synthesis by the corpus luteum during early pregnancy.     

Nerve growth factor induced changes in the Golgi apparatus of PC-12 rat pheochromocytoma cells as studied by ligand endocytosis,cytochemical and morphometric methods

Brain Cell Biology - Cells of the PC-12 rat pheochromocytoma cell line respond to nerve growth factor (NGF) by sprouting neurites and biochemically differentiating into sympathetic ganglion-like...     

Holistic process development to mitigate proteolysis of a subunit rotavirus vaccine candidate produced in Pichia pastoris by means of an acid pH pulse during fed-batch fermentation

To meet the challenges of global health, vaccine design and development must be reconsidered to achieve cost of goods as low as 15¢ per dose. A new recombinant protein-based rotavirus vaccine candidate derived from non-replicative viral subunits fused to a P2 tetanus toxoid CD4(+) T cell epitope is currently under clinical development. We have sought to simplify the existing manufacturing process to meet these aims. To this end, we have taken a holistic process development approach to reduce process complexity and costs while producing a product with the required characteristics. We have changed expression system from Escherichia coli to Pichia pastoris, to produce a secreted product, thereby reducing the number of purification steps. However, the presence of proteases poses challenges to product quality. To understand the effect of fermentation parameters on product quality small-scale fermentations were carried out. Media pH and fermentation duration had the greatest impact on the proportion of full-length product. A novel acidic pH pulse strategy was used to minimize proteolysis, and this combined with an early harvest time significantly increased the proportion of full-length material (60–75%). An improved downstream process using a combination of CIEX and AIEX to further reduce proteases, resulted in maintaining product quality (95% yield).