• KSBB Journal
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• v.13 no.2
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• pp.133-140
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• 1998

Using rlFN-$\alpha$ and rhGH as the model proteins, the refolding performances of the published processes were evaluated and compared. Key engineering parameters such as the type of denaturant and this concentration, protein concentration in the refolding buffer, and pH and ionic strength of the buffer were experimentally investigated. Furthermore, the role of a co-solvent of surfactant type in aggregation reduction was also studied. Of the denaturants tested (8M urea, 6M guanidine HCI, 0.5% SDS), SDS at alkaline pH (9.5) and ambient temperature gave the highest recovery yield. The SDS process was effective in the refolding of observed where dissolution proceeded better under lower strength (10 mM) but aggregation was suppressed under higher strength (>50 mM.) When PEG-4000 and/or Tween were added as co-solvent or refolding-enhancing additive, 1.6-2 times higher yield was realized. The‘masking’of the hyrophobic patches located on the surface of the protein with the surfactant molecules was believed to be responsible for the considerable reduction in aggregation during refolding.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.592-596
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• 1994

The interaction between fibronectin (FN) and its receptors controls cell attachment and migration, two crucial events during monocyte development and differentiation. To investigate the functional role of FN and its receptor, we have studied adhesion of monocyte to two different regions of FN (38- and 85-kDa domain), as well as the expression of the integrin during monocle differentiation. Anti-integrin Rl subunit antibody completely blocked the attachment of FN-coated latex beads to macrophage, but the effect of anti-integrin u4 antibody was much less significant. Rat monocyte expressed integrin $u4\beta1$ predominantly, while macrophage expressed $\alpha5\beta1$ as analyzed tv flow cvtometer and western blot. From these results, it can be suggested that these two integrins plan different roles during monocyte differentiation.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.11 no.1
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• pp.1-22
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• 1998

During the last few years, nitric oxide(NO) as a potent macrophage-derived effector molecule against a variety of bacteria, parasites, and tumors has received increasing attention. More recent studies suggest that NO also has antiviral effects in both murine and human cells. The objective of the current study was to determine the effect of Yongdamsagantang(YST) on the production of NO. Stimulation of mouse peritoneal macrophages with YST after the treatment of recombinant $interferon-{\gammer}(rlFN-{\gammer})$ resulted in the increased NO synthesis. YST had no effect on NO synthesis by itself. When YST was used in combination with $rIFN-{\gammer}$, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of YST on NO synthesis was shown 6 hour after treatment with $rIFN-{\gammer}$. This increase in NO synthesis was reflected as increased amount of inducible NO synthase(iNOS) protein. NO production was inhibited by $N^G-monomethyl-L-arginine$. The increased production of NO from $rIFN-{\gammer}$ plus YST-stimulated cells was decreased by the treatment with staurosporin. In addition, synergy between $rIFN-{\gammer}$ and YST was mainly dependent on YST-induced tumor necrosis $factor-{\alpha}(TNF-{\alpha})$ secretion. These results suggest that the capacity of YST to increase NO production from $rIFN-{\alpha}-primed$ mouse peritoneal macrophages is the result of YST-induced $TNF-{\alpha}$ secretion.