• Animal cells and systems
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• v.7 no.4
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• pp.309-315
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• 2003

Renal dipeptidase (RDPase, membrane dipeptidase, dehydropeptidase 1, EC 3.4.13.19) has been widely studied since it was first purified from porcine kidney brush border membrane. It was reported that RDPase activity in urine samples of acute and chronic renal failure patients decreases. Nitric oxide (NO) is a highly reactive free radical involved in a number of physiological and pathological processes. NO is able to act in a dual mode, leading either to induction of apoptosis or to blunted execution of programmed cell death. NO inhibited the RDPase release from porcine renal proximal tubules, which could be blocked by L-NAME. Chitosan, the linear polymer of D-glucosamine in $\beta$(1\longrightarrow4) linkage, not only reversed the decreased RDPase release by NO but also increased NO production in the proximal tubule cells. The stimulatory effect of NO on RDPase release from proximal tubules in the presence of chitosan must be different from the previously proposed mechanism of RDPase release via NO signaling pathway. Chitosan stimulated the RDPase release in the proximal tubules and increased RDPase activity to 220% and 250% at 0.1% and 1%, respectively. RDPase release was decreased to about 40% in the injured proximal tubules and was recovered in proportion to the increase of chitosan. Chitosan may be useful in recovery of renal function from $HgCl_2$injury.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.153-156
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• 2000

Xylan, the major hemicellulose component of many plants, occurs naturally in a partially acetylated form and lignin, the most resistant component in plant cell wall degradation, is also attached to ${\beta}-1,4-linked-D-xylose$ backbone through the ester linkage. Esterases are required to release the esterified substituent and acetyl esterases are important in the complete degradation of acetylated polysaccharides, like pectins and xylans. The gene(Axe) encoding acetyl xylan estarase(AXE) was isolated from genomic ${\lambda}$ library from Aspergillus ficuum. Nucleotide sequencing of the Axe gene indicated that the gene was separated with two intervening sequences and the amino acid sequence comparison revealed that it was closely related to that from A. awamori with the 92 % indentity. Heterologous expression of AXE was conducted by using YEp352 and Saccharomyces cerevisae 2805 as a vector and host expression system, respectively. The Axe gene was placed between GAL1 promoter and GAL7 terminator and then this recombinant vector was used to transform S. cerevisiae 2805 strain. Culture filtrate of the transformed yeast was assayed for the presence of AXE activity by spectrophotometry and, comparing with the host strain, four to five times of enzyme activity was detected in culture filtrate of transformed yeast.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.5
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• pp.598-606
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• 2010

This study investigated the nutritional quality of soybean meal (SBM) fermented by Aspergillus ($FSBM_A$) and/or followed by Lactobacillus fermentation ($FSBM_{A+L}$). Both fermented products significantly improved protein utilization of SBM with higher trichloroacetic acid (TCA) soluble true protein content, in vitro protein digestibility and available lysine content, especially in $FSBM_{A+L}$. Moreover, $FSBM_{A+L}$ produced a huge amount of lactic acid resulting in lower pH as compared to the unfermented SBM or soybean protein concentrate (SPC) (p<0.05). $FSBM_A$ and $FSBM_{A+L}$ raised 4.14% and 9.04% of essential amino acids and 5.38% and 9.37% of non-essential amino acids content, respectively. The ${\alpha}$-galactoside linkage oligosaccharides such as raffinose and stachyose content in $FSBM_A$ and $FSBM_{A+L}$ decreased significantly. The results of soluble protein fractions and distribution showed that the ratio of small protein fractions (<16 kDa) were 42.6% and 63.5% for $FSBM_A$ and $FSBM_{A+L}$, respectively, as compared to 7.2% for SBM, where the ratio of large size fractions (>55 kDa, mainly ${\beta}$-conglycinin) decreased to 9.4%, 5.4% and increased to 38.8%, respectively. There were no significant differences in ileal protein digestibility regardless of treatment groups. SPC inclusion in the diet showed a better protein digestibility than the SBM diet. In summary, soybean meal fermented by Aspergillus, especially through the consequent Lactobacillus fermentation, could increase the nutritional value as compared with unfermented SBM and is compatible with SPC.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.76-81
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• 1999

Exo-polysaccharide obtained from the submerged cultivation of Ganoderma lucidum mycelium was fractionated. The structural analysis of the acidic exo-polysaccharide fraction (BWS-DA-GI), showing high antitumor activity, was carried out and compared to the mycelial acidic fraction (MWS-DA-GI). The major sugar constituents of the fraction of BWS-DA-GI were glucose, galactose and mannose in the molar ratio of 2.5 : 2.1 : 2.5. The minor components in this fraction were xylose and fucose. While the major sugar constituents of the mycelial acidic fraction of MWS-DA-GI were galactose, fucose, mannose and glucose. The trace components in this fraction was xylose. From the results of periodate oxidation, Smith degradation, affinity chromatography and methylation analysis, the chemical structures of the two fractions, BWS-DA-GI and MWS-DA-GI were both determined as ${\beta}-1,3$ glucans. It was also estimated that BWS-DA-GI had a $1{\rightarrow}6$ glucosidic linkage and MWS DA-GI had $1{\rightarrow}4$ and $1{\rightarrow}6$ glucosidic linkages. The molecular weights of these fractions, MWS-DA-GI and MWSDA-GI were estimated as $1.2{\times}10^6\;and\;1.0{\times}10^6$ dalton, respectively.