• Journal of Plant Biology
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• v.37 no.3
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• pp.285-292
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• 1994

Ultrastructural changes in Panax ginseng C. A. Meyer mesophyll chloroplasts and variation of thylakoid membrane protein in responce to the light intensity were studied in leaves of two-y-old plants exposed to two different light intensities under field coditions. The leaves were allowed to function for three months after emergence under two contrasting light conditions. The ginseng chloroplasts of 5% light were filled with highly stacked grana of condensely arrayed thylakoids, so that the stroma space was hardly observed. In contrast, chloroplasts from leaves at 100% sunlight had fewer thylakoid membranes and smaller grana stacks. The number of osmiophilic globules increased. Total Chl content and Chl b content were lower at 100% sunlight than 5% sunlight. The thylakoid membrane proteins in the leaves grown at 100% sunlight showed lower CPIa, LHCII and CP29 than those with 5% sunlight. This effect was most obvious for LHCII. Polypeptides showed major bands at 90, 64, 29-30, 22 and 14 kD, and minor bands at 59, 58, 54, 52, 49, 46, 44, 35, 23, 21 and 18-19 kD. All these bands were lower in intensity in the leaves exposed to 100% sunlight. Moreover, the bands at 58-59, 46-47 and 23 kD disappeared.

• The Korean Journal of Physiology
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• v.20 no.2
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• pp.209-217
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• 1986

The functional molecular weight of band 4.5 polypeptide was measured by applying the classical target theory to radiation inactivation data of the cytochalasin B binding. Band 4.5 polypeptides purified from human erythrocyte membranes were irradiated at -45 to $-50^{\circ}C$ with an increasing dose of 1.5 MeV electron beam, and after thawing, cytochalasin B binding activities were assayed. Each activity measured was reduced as a simple exponential function of radiation dose. $D_{37}$, dose appeared to be 6.7 mega rads, from which the target size (radiation sensitive mass) of band 4.5 polypeptide was calculated to be 95,500 daltons. This result with other informations available in literature suggests that band 4.5 polypeptide may exist as a dimer in human erythrocytes.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.160-167
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• 1998

Chemical studies of nitrogen compounds of Panax ginseng seem relatively rare, Probably due to the isolation difficulties, subsequently the investigations of biological activities are little. The experimental conditions were established for highly complete extraction of peptides (basic, acidic and neutral) from Panax ginseng. This task was achieved by applying the follow isolation procedure: 1 , the sequential extraction with water, 0.1% TFA in 20% acetonitril and buffer pH 6.5 (water-pyridine-acetic acid 100:3:900) : 2, fractionation by ultrafiltration : 3, n-butanol extraction 4, cation- and anion-exchange chromatography : 5, chromato-electrophoresis. The comparison of red ginseng (xylem Sl pith part) and red ginseng inside white (xylem Sc pith part) was also provided. To analyze the peptide mixture the chromato-electrophoresis method of separation was applied. Optimal conditions for peptides mapping of sample were explored. Our experiments revealed the quantitative difference of peptide between xylem & pith and phloem & cortex part. We have also found the qualitative difference in the composition of polypeptides between normal red ginseng (xylem Sc pith part) and red ginseng inside-white (xylem St pith part)

• The Korean Journal of Zoology
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• v.26 no.1
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• pp.1-17
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• 1983

The synthesis of myosin, actin, tropomyosin and troponin in the cultured muscle cells of chick embryo during the differentiation were analyzed. The synthesis of myosin and actin were very active prior to the myoblast fusion while the troponin synthesis became active after the fusion. Tropomyosin was synthesized practically constantly throughout the culture period. Several proteins were detected in the muscle-conditioned medium strongly suggesting that the cells in culture released polypeptides which might act on the membrane of neighboring cells cells to initiate the fusion.

• Molecules and Cells
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• v.37 no.1
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• pp.1-8
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• 2014

Mammalian-cell messenger RNAs (mRNAs) are generated in the nucleus from precursor RNAs (pre-mRNAs, which often contain one or more introns) that are complexed with an array of incompletely inventoried proteins. During their biogenesis, pre-mRNAs and their derivative mRNAs are subject to extensive cis-modifications. These modifications promote the binding of distinct polypeptides that mediate a diverse array of functions needed for mRNA metabolism, including nuclear export, inspection by the nonsense-mediated mRNA decay (NMD) quality-control machinery, and synthesis of the encoded protein product. Ribonucleoprotein complex (RNP) remodeling through the loss and gain of protein constituents before and after pre-mRNA splicing, during mRNA export, and within the cytoplasm facilitates NMD, ensuring integrity of the transcriptome. Here we review the mRNP rearrangements that culminate in detection and elimination of faulty transcripts by mammalian-cell NMD.

• Journal of Nutrition and Health
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• v.26 no.5
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• pp.585-592
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• 1993

In order to investigate the hypocholesteremic effect of soybean perptides, soybean protein(ISP), casein(CNP), their peptic hydrolyzates fractionated by acid precipitation at different pH's(SHT, SH8, SH6, SH4, CHT, CH5, CH4) and amino acid mixtures of the same composition as the proteins(SAA, CAA) were fed to rats and the concentration of serum cholesterol was measured. Then in vitro digestibility and molecular weight distribution of the peptides by pepticpancreatic hydrolysis was measured by FPLC. The lower the in vitro digestibility of peptides is, the lower the concentration of serum cholesterol becomes(r=0.986) and the higher the ratio of macropeptides is, the lower the concentration of serum cholesterol becomes(r=-0.932) in rats. These results suggest that the in vitro digestibility of peptides has close relationship to the concentration of serum cholesterol in rats and non-digestible meacropeptides or polypeptides especially more than 1 kDa, formed through digestion in gut, may lower the serum cholesterol in rats.

• Journal of Plant Biology
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• v.39 no.4
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• pp.257-263
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• 1996

Flower-inducing activity in the phloem exudata of Pharbitis cotyledons was investigated using the bioassay of Pharbitis and Lemna. By SDS-PAGE and 2-D gel electrophoresis of the phloem exudate, two polypeptides of 11 kDa and of approximately 32 kDa (pI 6.9) showing qualitative changes during the flower induction were detected. A polypeptide of approximately 20 kDa (pI 4.8) specifically labeled in vivo with [35S]methionine was found during the inductive dark period in Pharbitis cotyledon tissues. The polypeptide of the equivalent molecular mass and with the identicl pI value was also detected by in vitro translation assay. Thus, it is assumed that the 20 kDa polypeptide plays a role in the process of flower induction in Pharbitis cotyledons.

• Bulletin of the Korean Chemical Society
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• v.19 no.2
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• pp.189-193
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• 1998

Carboxypeptidase-B (CPB) is involved in the biosynthesis of numerous peptide hormones and neurotransmitters. CPB catalyzes hydrolysis of the basic amino acids from the C-terminal position in polypeptides during posttranslational prohormonal processing. Various peptides containing thiaarginine residue at C-terminal position were synthesized and tested for their hydrolysis by CPB. A colorimetric assay, employing Ellman's reagent to detect the thioguanidine released upon hydrolysis of the dipeptide substrates, showed that thiaarginine is a suitable mimetic for arginine. Kinetic studies on the four substrates, Z-L-Ala-DL-thia-Lys, Z-L-Ala-DL-thia-Arg, Z-L-Lys-DL-thia-Arg, and Z-L-Lys(Boc)-DL-thia-Arg, gave Km (mM) of 0.66, 5.08, 0.024, and 0.006 and kcat (min-1) of 340, 5200, 151 and 335, respectively.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.163.4-164
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• 2003

Peptide deformylase (PDF) is essential and unique to bacteria for cytoplasmic protein synthesis, but not required in eukaryotes, thus making it an attractive target for the discovery of novel antibacterial drugs. Protein synthesis in eubacteria, under normal conditions, is initiated by formyl-methionyl-tRNA. PDF removes the formyl-group of N- formylmethionine of newly synthesized polypeptides to produce a mature protein. In this study, a pdf gene from Staphylococcus aureus 6538p was cloned in pET-14b vector and transformed in Escherichia coli BL21 (DE3). (omitted)

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.816-828
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• 1995

During the industrial preparation and the storage of foods, the side chain of some protein-bound amino acids can react chemically each other or with other molecules present in the food. The following reactions have been described : destruction of amino acids, racemization, protein-protein interactions, reactions of proteins with reducing sugars, oxidizing agents, or polyphenols. Apart from total destruction, the main reacitons are the forming of Maillard reactions products(e.g. fructoselysine) and the crosslinking with other amino acids in the same or in another protein molecule(e.g. lysinoalanine). The most often involved amino acid is lysine because of its free functional ${\varepsilon}-amino$ acid group. Generally derivatives of amino acids or crosslinks in polypeptides influence the bioavailability and the overall digestibility of the protein. This work reviews the technological, analytical, nutritional, and physiological problems related to the formation of fructoselysine and lysinolalnine in human foods, and evaluates the possible health risk for humans. A summary of the available information is of help in considering whether or not the presence of fructoselysine/lysinoalanine in foods represents a danger to man. The reduction in protein quality through these reactions is not a problem for the general population, but it is extremely important in infant foods, since infants are often nourished with a limited number of food product(e.g. formular foods) which are sensitive to the Mailard reaction.