• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.29-33
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• 2004

Low molecular weight silk fibroin (LMSF), which was prepared by hydrolysis of silk fibroin using high-temperature and high-pressure method, was found to inhibit the oxidation of L-3,4,-dihydroxyphenylalanine (L-DOPA) catalyzed by mushroom tyrosinase (EC 1.14.18.1). LMSF contained mostly free amino acids such as L-glycine, L-alanine, and L-serine and oligopeptides, mainly glycine-alanine dimer. As a result of analyzing the inhibition kinetics from Lineweaver-Burk plots, L-glycine and glycine-alanine dimer showed noncompetitive behavior while uncompetitive behavior was observed in L-alanine, and L-serine. When weight percent concentration of ${ID_50}$ was compared, L-glycine was most effective on the inhibition and LMSF was also good enough for the inhibition effect of tyrosinase activity. LMSF showed a mixed-type inhibition and the inhibitory mechanism of LMSF might be caused by free amino acids and oligopeptides. As a result of spectroscopic observation with time, initial rate of increase of DOPAchrome decreased remarkably and the time to reach maximum absorbance increased as an increase of the concentration of L-glycine, meaning that L-glycine made itself mainly responsible for the formation of chelate with ${Cu^2+}$ in tyrosinase. However, in case of L-alanine, L-serine, and especially glycine-alanine dimmer, the production of DOPAchrome after an arrival at maximum absorbance decreased, indicating the production of adducts through the reaction with DOPAquinone.

• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.81-86
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• 1995

A Streptomyces strain YS-943, which produced amino acid antimetabolite, was isolated from soil. During the course of screening for new amino acid antimetabolites from the culture broth of Actinomycetes, we found that the strain produced a substance active against Gram-positive bacteria and its activity was reversed by L-methionine and L-histidine on the synthetic minimal agar medium in the culture broth.The morphological and cultural characteristics serve to identify the producing organism strain YS-943 as the genus Streptomyces. Fermentation was carried out in the synthetic medium at 28$\CIRC$C for 48 hours. The fermentation yield reached about 12 mg per liter of the broth. The YS-943 substance was obtained as white powder, mp 194$\CIRC$C and has the molecular formular of C$_{4}$H$_{8}$N$_{2}$O$_{4}$. Its structure was determined to be o-carbamyl-D-serine by spectroscopic data. It is active against some Gram-positive bacteria and reversed by L-methionine and L-histidine.

• Clinical and Experimental Reproductive Medicine
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• v.20 no.1
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• pp.19-29
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• 1993

Plasminogen activator (PA)-plasmin system in follicular fluid is involved in the process leading to follicular rupture at ovulation. It is well known that PA is closely associated with cellular differentiation and tissue remodeling on evidences from the study of normal and malignant tissues. This study was designed to ascertain a potential role of PA in the ovarian folliculogenesis. Immature Sprague-Dawley rats were injected with pregnant mare serum gonadotropin, followed by injection of serine protease inhibitor (SPI; mixture of 1 mol/L benzamidine and 1 mol/L amino-caproic acid) into the unilateral ovarian bursa. In the control study, mechanical effect of bursal injection and contralateral ovarian effect SPI were ruled out. Total antral follicular areas relative to total ovarian cross-sectional areas was siginificantly lower in SPI-injected ovary than in saline-injected ovary. SPI injection decreased the relative antral follicular area by 33 % respectively. Electron microscopic finding of granulosa cell in the atretic follicle showed the presence of pyknotic nucleus, blurring of neucleolemma, degeneration of mitochondria and dilation of endoplasmic reticulum. After induction of ovulation with hCG, the number of oocytes released was significantly decreased in SPI-injected oviduct than in saline-injected oviduct. From above results, author discussed that PA may play a role not only in ovulation but also in some processes of folliculogenesis.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1531-1534
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• 2009

(2S,3R)-3-Hydroxy-2-(hydroxymethyl)-3,6-dihydro-2H-pyridine 8, an important precursor for the synthesis of polyhydroxylated piperidine azasugars, has been prepared from L-serine. Highly stereoselective nucleophilic addition to amino aldehyde 5 gave the corresponding allylic alcohol 6 which proceeded to give dihydro-2H-piridine 7a via a Grubbs II catalyzed RCM. Stereoselective H-bond directed epoxidation of allylic alcohol led to the oxiranyl alcohol 9 which was easily converted to L-deoxyaltronojirimycin by regioselective ring opening.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.99-109
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• 2022

This study is the first report on production and characterization of the enzyme from an Ornithinibacillus species. A 4.2-fold increase in the extracellular protease (called L9^T) production from Ornithinibacillus caprae L9^T was achieved through the one-factor-at-a-time approach and response surface methodological optimization. L9^T protease exhibited a unique protein band with a mass of 25.9 kDa upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This novel protease was active over a range of pH (4-13), temperatures (30-80℃) and salt concentrations (0-220 g/l), with the maximal activity observed at pH 7, 70℃ and 20 g/l NaCl. Proteolytic activity was upgraded in the presence of Ag⁺, Ca²⁺ and Sr²⁺, but was totally suppressed by 5 mM phenylmethylsulfonyl fluoride, which suggests that this enzyme belongs to the serine protease family. L9^T protease was resistant to certain common organic solvents and surfactants; particularly, 5 mM Tween 20 and Tween 80 improved the activity by 63 and 15%, respectively. More importantly, L9^T protease was found to be effective in dehairing of goatskins, cowhides and rabbit-skins without damaging the collagen fibers. These properties confirm the feasibility of L9^T protease in industrial applications, especially in leather processing.

• KSBB Journal
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• v.21 no.1 s.96
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• pp.20-27
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• 2006

The fibrinolytic activities of soluble proteins extracted from seeds of Coix lacryma-jobi L., Carthamus tinctorius L. and Malva venicillata L. were studied. Fibrinolytic activity of extract from C. lacryma-jobi L. showed 1.3 times higher than plasmin used as positive control. The fibrinolytic enzyme was confirmed and extracted directly from seed of C. lacryma-jobi L. by a fibrin zymography. The protein was composed of a single polypeptide and its apparent molecular weight was found to be 7.8 kDa, as judged by SDS-polyacrylamide gel electrophoresis. The effect of temperature for the proteolytic enzyme activity were stabilized above $50^{\circ}C$ and then dramatically decreased. Also, the enzyme activity was clearly inhibited by APMSF, PMSF and TPCK, suggesting that it is a member of the chymotrypsin-like serine pretense. In addition, effects of gamma-irradiated on seed of each plants were revealed that 8 Gy and 64 Gy were higher than others. This result shown that gamma-irradiation of seeds were capable to increase the fibrinolytic activity. All these results suggest the pretense is a fibrinolytic enzyme belong to a family of chymotrypsin-like serine pretense.

• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.75-87
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• 1994

The metal complexes containing amino acidic ligands were prepared by using 11 kinds of amino acids as ligands and Ni, Cu, Co, Zn, Fe as a central metal. The starting was continued for 4hrs at room temperature. But Bis(D,L-Serine)Ni (II), and (D,L-Serine)Co (II) were prepared by heating method($80^{\circ}C$). In order to investigated reaction activity of Bis(D,L-Aspartato) Metal(II), stirring time was varied and Bis(D,L-Tyrosine ) Metal(II) used different divalent metal salts. We anticipate getting a great value from these prepared complexes as a monomer and a catalyst of polymerization which has peculier characteristics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.708-712
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• 2006

The chemical properties of yellow and red onion were investigated and analyzed to provide basic data for functional food materialization and processing. The moisture and nitrogen free extract contents of yellow and red onion were 92.80%, 5.13% and 92.47%, 5.59%, respectively. Mineral components of yellow and red onion were rich in K (123.64 and 114.41 mg%), Na (34.09 and 33.57 mg%) and P (27.04 and 20.56 mg%). The major free sugar of yellow onion were glucose (744.2 mg%) and fructose (705.9 mg%). Whereas major free sugar of red onion were sucrose (692.8 mg%) and fructose (517.3 mg%). Glutamic acid, phenylalanine and aspartic acid in yellow and red onion were major amino acids. Abundant free amino acids in yellow onion were hydroxy-L-proline (27.34 mg%), L-serine (27.34 mg%) and L-arginine (26.25 mg%). Abundant free amino acids in red onion were L-glutamic acid (16.35 mg%), ammonium chloride (15.22 mg%) and L-serine (10.93 mg%). Ascorbic acid contents are higher in red onion (28.34 mg%) than in yellow onion (19.20 mg%). Quercetin and total polyphenol of yellow and red onion were 15.24 mg%, 5.70 mg% and 0.319 mg/g and 0.248 mg/g, respectively.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.2
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• pp.187-193
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• 2012

Serine proteases are major insect enzymes involved in the digestion of dietary proteins and in the process of blood meal digestion. In this study, cDNA was constructed using the whole body of Laccotrephes japonensis. The flanking sequences of the 5- and 3- end of this gene were characterized by RACE-PCR. Sequence analysis showed that this gene contained a 963-bp ORF encoding 320 amino acids. The deduced amino acid sequence showed 62% identity with the Creontiades dilutus serine protease, 58% with the Lygus lineolaris trypsin precursor, and 54% with the Triatoma infestans salivary trypsin. To assess the expression of the L. japonensis serine protease (JGsp), the JGsp gene was cloned into a baculovirus transfer vector, pBac-1, and expressed in Sf9 cells (Spodoptera frugiperda). SDS-PAGE and western blot analysis have shown that the JGsp recombinant protein was a monomer with a molecular weight of about 32 kDa. Recombinant JGsp has shown activity in the protease enzyme assay using gelatin as a substrate.

• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.516-520
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• 1994

New synthetic method of optically active 2-amino-3-phosphonopropionic acid from L-serine was developed and their phosphonotripeptides, phthalylglycylglycyl-2-amino-3-(diethylphosphono)-propionic acid methyl ester and phthalylglycyl-L-phenylalanyl-2-amino-3-(diethylphosphono)propionic acid methyl ester, were synthesized by coupling reaction of amino acids with 2-amino-3-phosphonopropionic acid methyl ester.