• Journal of Sericultural and Entomological Science
• /
• v.49 no.2
• /
• pp.43-46
• /
• 2007

Analysis of general ingredients and amino acid content in dried silkworm feces which were extracted with hot water, EtOH, MeOH for developing new income source of rearing farm, seeking high additive value material and industrialization of silkworm feces. In the analysis of general ingredient content by extracting solution, raw protein and ash contents were increased with MeOH, EtOH, hot water. And raw fat showed higher contents by the order of EtOH > MeOH > hot water. The inorganic matter content showed a little difference among collection times of silkworm feces. Hot water was most effective extracting solution for total amino acid, and no significant difference between EtOH and MeOH. According to the time, there were no significant difference in amino acid contents. When extracted with hot water, Glu content was highest content and order of others is Asp > Gly > Ala > Leu > Thr > Ser among 18 amino acids.

• BMB Reports
• /
• v.31 no.4
• /
• pp.364-369
• /
• 1998

Insect plasma protein is abundant in the hemolymph of holometabolous insect larvae and is used as a source of amino acids and energy for construction of adult structures during metamorphosis. In order to understand the mechanism of decomposition of larval plasma proteins by hemocyte protease, we tried to purify a cysteine protease from the hemocyte lysate by using Carbobenzoxy-L-Phenylalanyl-L-Arginine-4-Methyl-Coumaryl-7-Amide (Z-Phe-Arg-MCA) as substrate and to identify plasma proteins that are selectively susceptible to the purified protease. Here, we describe the purification and characterization of a cysteine protease that specifically hydrolyzes the plasma protein of the coleopteran insect, Tenebrio molitor, larvae. The molecular mass of this enzyme was 25 kDa, as determined by SDS-PAGE under reducing conditions. The amino acids sequence of its $NH_{2}-terminus$ was determined to be Leu-Pro-Gly-Gln-Ile-Asp-Trp-Arg-Asp-Lys-Gly. This sequence contained Pro, Asp, and Arg residues, conserved in many papain superfamily enzymes. The specific cysteine protease inhibitors, such as E-64 and leupetin, inhibited its hydrolytic activity. One plasma protein with a molecular mass of 48 kDa was selectively hydrolyzed within 3 h when the purified enzyme and plasma proteins were incubated in vitro. However, the 48 kDa protein was not hydrolyzed by the purified 25 kDa protease in the presence of E-64. Western blotting analysis at various developmental stages showed that the purified enzyme was detected at larvae, pupae, and adult stages, but not the embryo stage.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.3
• /
• pp.406-409
• /
• 2002

The effect of refeeding with various single essential amino acids on the recovery of plasma insulin-like growth factor-I (IGF-I) concentration in fasted young chickens was examined. Young chickens (29 days of age) were divided into 15 experimental groups. Chickens in one group were fed on the commercial diet ad libitum for 4 days. The remaining 56 chickens in 14 experimental groups were fasted. After 2 days of fasting, 52 chicks in 13 fasted groups were refed with one of the following experimental diets for 2 days. Eleven experimental diets were protein-free diets supplemented with one of 11 essential amino acids (Arg, Gly, His, Ileu, Leu, Met, Phe, Lys, Thr, Trp, Val). The remaining 2 experimental diets were a protein-free diet containing 11 essential amino acids and a protein-free diet not supplemented with amino acids. Birds in the remaining fasted group continued to be fasted for 2 days. Fasting for 2 days markedly reduced plasma IGF-I concentration. When fasted chickens were refed the protein-free diet containing either Gly alone or all essential amino acids, plasma IGF-I concentration was recovered to the level similar to that of fed chickens. Protein-free diet alone, however, failed to restore the reduced IGF-I concentration in plasma. Body weight loss modulated by feeding with protein-free diets supplemented with various single essential amino acids was associated with changes in plasma IGF-I concentrations. We concluded that body weight loss by feeding with a protein-free diet was lower than that of fasted chickens and that body weight loss associated with the decrease in plasma IGF-I concentration was modulated by feeding with protein-free diets containing various single essential amino acids.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.6
• /
• pp.805-810
• /
• 2000

An antifungal protein antagonistic to the rice blast fungus, Pyricularia oryzae was purified from Paenibacillus macerans PM-1 by ammonium sulfate fractionation, Q Sepharose Fast Flow column chromatography, Phenyl Sepharose CL-4B column chromatography and Superose 12 gen filtration. An apparent molecular mass of the purified antifungal protein was determined as 8 kDa by SDS-PAGE and 9 kDa by analytical gel filtration, respectively, suggesting that the purified protein is a monomer. The antifungal protein was stable at pH range from 7-12 and up to $100^{\circ}C$. The protein was also stable at 0.1-1% Tween 20 and Triton X-100. The N-terminal amino acid sequence of the antifungal protein was Thr-Glu-Leu-Pro-Leu-Gly-Ile-Val-Met-Asp-Lys-Tyr-Thr-Asp-Ala-Phe-Lys-Phe-Asp-Met-Phe. Comparison of the determined sequence with other peptide and DNA sequences did not reveal homology at all. Therefore, the purified antifungal protein was speculated to be a novel protein. The condidial germination in vitro of P. oryzae KJ301:93-39 by the purified protein ($5.9{\mu} g/ml$) was limited to $9{\pm}3.2%$ only, compared with $69{\pm}2.4%$ of the control. Ungerminated conidia were swollen at basa and mid cell by the purified protein. In vivo bioassay for inhibition of conidial germination of P. oryzae KJ 301, one of the most predominating racesin Korea. the purified protein ($5.9{\mu} g/ml$)strongly inhibited the conidial germination. The conidia, even though germinated, could not develop any further to produce appressoria efficiently.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.9
• /
• pp.1327-1334
• /
• 2015

The current study determined the apparent or standardized ileal digestibility of amino acids (AID or SID of AA) in growing pigs fed diets containing three protein feedstuffs with different fiber characteristics at two dietary crude protein (CP) levels. Twenty boars ($Yorkshire{\times}Landrace$) with average initial body weight of $35({\pm}2.6)kg$ were fitted with a simple T-cannula at the distal ileum. These pigs were offered six diets containing soybean meal (SBM), canola meal (CM) or corn distillers dried grains with solubles (corn-DDGS) that were either adequate (19%) or marginal (15%) in CP using a triplicated $6{\times}2$ Youden Square Design. Except for Met, Trp, Cys, and Pro, AID of AA was greater (p<0.05) in the SBM diet compared with the CM diet. Apparent ileal digestibility for Gly and Asp was greater (p<0.05) in the SBM diet compared with the corn-DDGS diet. The AID of Ile, Leu, Phe, Val, Ala, Tyr, and Asp was greater (p<0.05) in the corn-DDGS diet compared with the CM diet. Standardized ileal digestibility of AA was greater (p<0.05) in the SBM diet compared with the CM diet for all AA except Trp and Pro. The SID of Ile, Leu, Val, Ala, Tyr, and Asp was greater (p<0.05) in the corn-DDGS diet compared with the CM diet. It was concluded that protein feedstuff affects ileal AA digestibility and is closely related to dietary fiber characteristics, and a 4-percentage unit reduction in dietary CP had no effect on ileal AA digestibility in growing pigs.

• BMB Reports
• /
• v.29 no.5
• /
• pp.429-435
• /
• 1996

To investigate the structure-antagonistic relationship of the cyclohexapeptide L-659,877, a selective NK-2 tachykinin receptor antagonist, seven analogues were chemically synthesized by a solid phase method. The agonistic and antagonistic activities of the analogues were evaluated by contraction assay using the smooth muscle of guinea pig trachea (GPT) containing the NK-2 receptor. It was shown that the aromatic ring of Phe at position 3 and the sulfur group of Met at position 6 in L-659,877 were essential for binding to the NK-2 receptor. Decrease in antagonistic activity of L-659,877 caused by substituting Leu for Nle at position 5 indicates that the ${\gamma}$ methyl group and side chain length of Leu plays an important role in its antagonistic action. Although the activity was slightly lower than L-659,877, cyclo $[{\beta}Ala^{8}]NKA(4-10)$ (analogue 1) showed potential antagonistic activity for the NK-2 receptor. It was confirmed that the expansion of the ring in L-659,877 by substitution of ${\beta}Ala$ for Gly at position 4 stabilized its conformation monitored by CD spectra. The results suggest that analogue 1 can be used as a new leader compound to design a more powerful, selective, and stable NK-2 receptor antagonist.

• Journal of Life Science
• /
• v.9 no.1
• /
• pp.26-34
• /
• 1999

A thermostable pullulanase has been isolated and purified from Thermus caldophilus GK-24 to a homogeneity by gel-filtration and ion-exchange chromatography. The specific activity of the purified enzyme was 431-fold increase from the crude culture broth with a recovery of 11.4%. The purified enzyme showed $M_{r}$ of 65 kDa on denaturated and natural conditions. The pI of the enzyme was 6.1 and Schiff staining was negative, suggesting that the enzyme is not a glycoprotein. The enzyme was most active at pH 5.5. The activity was maximal at $75^{\cire}C$ and stable up to $95^{\cire}C$ for 30 min at pH 5.5. The enzyme was stable to incubation from pH 3.5 to pH 8.0 at $4^{\cire}C$ for 24hr. The presence of pullulan protected the enzyme from heat inactivation, the extent depending upon the substrate concentration. The activity of the enzyme was simulated by $Mn^{2+}$ ion, }$Ni^{2+}$, $Ca^{2+}$, $Co^{2+}$ ions. The enzyme hydrolyzed the ${\alpha}$-1,6-linkages of amylopectin, glycogens, ${\alpha}$, ${\beta}$-limited dextrin, and pullulan. The enzyme caused the complete hydrolysis of pullulan to maltotriose and the activity was inhibited by $\alpha$, $\beta$, or $\gamma$-cyclodextrins. The $NH_{2}$-terminal amino acid sequence [(Ala-Pro-Gln-(Asp of Tyr)-Asn-Leu-Leu-Xaa-ILe-Gly-Ala(Ser)] was compared with known sequences of various sources and that was compared with known sequences of various sources and that was different from those of bacterial and plant enzymes, suggesting that the enzymes are structurally different.

• The Plant Pathology Journal
• /
• v.33 no.4
• /
• pp.402-409
• /
• 2017

Cyclic dipeptides (CDPs) are one of the simplest compounds produced by living organisms. Plant-growth promoting rhizobacteria (PGPRs) also produce CDPs that can induce disease resistance. Bacillus vallismortis strain BS07 producing various CDPs has been evaluated as a potential biocontrol agent against multiple plant pathogens in chili pepper. However, plant signal pathway triggered by CDPs has not been fully elucidated yet. Here we introduce four CDPs, cyclo(Gly-L-Pro) previously identified from Aspergillus sp., and cyclo(L-Ala-L-Ile), cyclo(L-Ala-L-Leu), and cyclo(L-Leu-L-Pro) identified from B. vallismortis BS07, which induce disease resistance in Arabidopsis against Pseudomonas syringae infection. The CDPs do not directly inhibit fungal and oomycete growth in vitro. These CDPs require PHYTOALEXIN DEFICIENT4, SALICYLIC ACID INDUCTION DEFICIENT2, and NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 important for salicylic acid-dependent defense to induce resistance. On the other hand, regulators involved in jasmonate-dependent event, such as ETHYLENE RECEPTOR1, JASMONATE RESPONSE1, and JASMONATE INSENSITIVE1, are necessary to the CDP-induced resistance. Furthermore, treatment of these CDPs primes Arabidopsis plants to rapidly express PATHOGENESIS-RELATED PROTEIN4 at early infection phase. Taken together, we propose that these CDPs from PGPR strains accelerate activation of jasmonate-related signaling pathway during infection.

• Analytical Science and Technology
• /
• v.13 no.4
• /
• pp.494-503
• /
• 2000

A 21-residue peptide corresponding to amino acids 84-104 of $p16^{INK4A}$, the tumor suppressor, has been synthesized and its structure was studied by Circular Dichroism, $^1H$ NMR spectroscopy and molecular modeling. A p16-derived peptide (84-104 amino acids) forming stable complex with CDK4 and CDK6 inhibits the ability of CDK4/6 to phosphorylate pRb in vitro, and blocks cell-cycle progression through G1/S phase as shown in the function of the full-length p16. Its NMR spectral data including NOEs, $^3J_{NH-H{\alpha}}$ coupling constants, $C_{\alpha}H$ chemical shift, the average amplitude of amide chemical shift oscillation and temperature coefficients indicate that the secondary structure of a p16-derived peptide is similar to that of the same region of full-length p16, which consists of helix-turn-helix structure. The 3-D distance geometry structure based on NOE-hased distance and torsion angle restraints is characterized by ${\gamma}$-turn conformation between residues $Gly^{89}-Leu^{91}$(${\varphi}_{i+1}=-79.8^{\circ}$, ${\varphi}_{i+1}=60.2^{\circ}$) as evidenced in a single crystal structure for the corresponding region of p18 or p19, but is undefined at both the N and C termini. This compact and rigid ${\gamma}$-turn region is considered to stabilize the structure of p16-derived peptide and serve as a site recognizing cyelin dependent kinase, and this well-defined ${\gamma}$-turn structure could be utilized for the design of anti-cancer drug candidates.

• Applied Biological Chemistry
• /
• v.30 no.4
• /
• pp.345-350
• /
• 1987

Three lots of mejues were prepared with three different strains of Aspergillus oryzae, Bacillus natto, Bacillus subtilis and one was made by conventional method. The four different soy bean pastes were analyzed for compositions of free amino acids, sugars and organic acids during the period of fermentation. Amino nitrogen contents in the samples of A. oryzae were higher than others throughout the aging period. The amounts of each amino acids were varied markedly among the samples after 20-days, while glutamic acid, aspartic acid, lysine and phenylalanine were dominant in all samples after 90-days. Glucose contents were found to be in the range of $0.46{\sim}2.66%$ and other sugars of fructose, sucrose, rhamnose and maltose were less than 0.35%. The levels of total free sugar were relatively higher in the samples prepared with B. natto than others. Citric, lactic, malic, acetic and oxalic acids were identified, and the content of lactic acid was higher in the samples of A. oryzae, whereas citric acid was higher in conventional method.