• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.714-720
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• 1989

Effects of acetylation on conformational changes of glycinin was studied using solvent perturbation, second derivative spectroscopy, near uv circular dichroism spectra and viscosity. Glycinin with purity of more than 93% was used for the experiment. Modification was carried out with acetic anhydride and glycinin with lysine residue modification of 0%, 28%, 65%, 85%, and 95% were used for the experiment. The result of solvent perturbation using some selected perturbants, such as glycerol, ethylene glycol, and dimethyl sulfoxide revealed that acetylation has caused increase In solvent accessibility of tyrosine residues from less than 40% in native protein to more than 70% for 95% acetylated glycinin. This was confirmed by second derivative spectroscopy. Near ultraviolet circular dichroism revealed that the spectra of native and acetylated glycinin were almost identical differing only in intensity and no other useful information could be derived from it. However, in the case of 95% acetylated glycinin the influence of tryptophan on the spectrum was more pronounced Specific viscosity of glycinin also increased by modification, the extent of which depended upon the degree of acetylation. These results supported that acetylation had caused globular conformation of glycinin to be expanded and denatured.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.118-123
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• 2015

The structural transition of silk protein has been induced by various method including alcohol treatment. To know the effect of alcohol concentration on silk beads conformation, silk beads were prepared in different alcohol concentration (100%, 70%, and 50%) and then examined the infrared spectra of silk beads. Silk beads prepared in 100% alcohol showed at $1265cm^{-1}$ attributed ${\beta}-sheet$ conformation and did not showed a characteristic absorption peak from model drug. However, silk beads in 70% and 50% alcohol showed some peaks originated from model drug including $2933cm^{-1}$, $1069cm^{-1}$, and $973cm^{-1}$. These results means that the micro-environment of silk beads was affected by alcohol concentration.

• Archives of Pharmacal Research
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• v.15 no.4
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• pp.347-355
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• 1992

To elucidate structure of group "a" epitope, mouse antibodies that express idiotype monoclonal antibody and anti-idiotype monoclonal antibody against the group specific "a" determinant were purified by hydroxyapatite column. To obtain hepatitis B surface antigens (HBsAg). HBsAg positive blood was sequencially purified by ammonium sulfate precipitation, hydroxyapatite, sepharose 4B column chromatography and ultracentrifugation. The major protein (p25) and glycoprotein (gp30) of HBsAg were isolated by concanavalin-A-sepharose 4B. The ability of p25-gp30 among the HBsAg to inhibit the idiotype-anti-idiotype reaction was dependent on conformation, since reduced and alkylated p25-gp30 virtualy lost their inhibitory capacity when compared to native HBsAg. The data suggest that hepatitis B antigen is a conformational antigen critically dependent upon the disulfide bonds of p25-gp30.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.57-62
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• 1998

We have synthesized a 17-residue peptide with the amino acid sequence RQMKEDAKGKSEEELAD corresponding to residues 84-100 of chicken skeletal troponin C. This stretch of the protein sequence is in the middle one-third of the 32-residue 9-turn α-helix that connects the two globular domains of the dumbell-shaped molecule and includes the D/E linker helix. We describe here the solution conformation of the helix linker as studied by circular dichroism (CD) and two-dimensional nuclear magnetic resonance (2-D NMR) spectroscopy. The NOE connectivities together with the vicinal $^3J_{N{\alpha}}$ coupling constants suggest that the peptide exists in a fast conformational equilibrium among several secondary structure: a nascent helix near the N-terminus, a helix, and a substational population of extended and random coil forms. In addition, two interresidue α-α NOEs are observed suggesting a bent structure with a bend that includes the single glycine in position 92. These results are consistent with the ideas that in neutral solution the D/E linker region of the central helix in troponin C can adopt a helical conformation and the central helix may have a segmental flexibility around Gly 92.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.47-47
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• 2005

There are many different surface technologies currently applied for preparation of protein chips. However, it requires innovative surface chemistry for capture proteins to be immobilized on chip surface keeping their conformation and activity intact and their orientation right, while they bind tightly and densely in a given array spot. Proteogen has developed 'ProteoChip BP' coated with novel proprietary linker molecules $(ProLinker^{TM})$ for efficient and robust immobilizations of capture proteins by improving surface properties of molecular captures. It was demonstrated that $ProLinker^{TM}$ gave the best surface performance in preparation of protein microarray chip base plates among others currently available on the market. In particular, the $ProLinker^{TM}-based$ surface chemistry has demonstrated to provide excellent performance in preparation of 'Antibody Chip' for analysis of biomarkers as well as proteome expression profiles. The linker molecule has also shown to be well applicable for development of biosensors and micro-beads as well as protein microarray and nano-array. ProteoChip BP can be used either for preparation of high-density array by using a microarrayer or for preparation of 'Well-on-a-Chip' with low density array, which is better applicable for quantitative analysis of biomarkers or protein-protein interactions. The biomarker assay can be performed either by direct or sandwich methods of fluorescence immunoassay. Application of ProteoChip BP has been well demonstrated by the extensive studies of 1) tumor-marker assays, 2) new drug screening by using 'Integrin Chip' and 3) protein expression profile analysis. Some of experimental results will be presented.

• Bulletin of the Korean Chemical Society
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• v.21 no.3
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• pp.281-290
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• 2000

We varied recombination method of fenetic algorithm (GA), i.e., crossover step, to compare efficiency of these methods, and to find more optimum GA method. In one method (A), we select two conformations(parents) to be recombined by systematic combination of lowest energy conformations, and in the other (B), we select them in a ratio proportional to the energy of the conformation. Second variation lies in how to select crossover point. First, we select it randomly(1). Second, we select range of residues where internal energy of the molecule does not vary for more than two residues, select randomly among such regions, and we select either thr first (2a) or the second residue (2b) from the N-terminal side, or the first (2c) or the second residue (2d) from the C-terminal side in the selected region for crossover point. Third, we select longest such hregion, and select such residue(as cases 2) (3a, 3b, 3c or 3d) of the region. These methods were tested in a 2-dimensionl lattice system for 8 different sequences (the same ones used by Unger and Moult., 1993). Results show that compared to Unger and Moult's result(UM) which corresponds to B-1 case, our B-1 case performed similarly in overall. There are many cases where our new methods performed better than UM for some different sequences. When cooling factor affecting higher energy conformation to be accepted in Monte Carlo step was reduced, our B-1 and other cases performed better than UM; we found lower energy conformers, and found same energy conformers in a smaller steps. We discuss importance of cooling factor variation in Monte Carlo simulations of protein folding for different proteins. (A) method tends to find the minimum conformer faster than (B) method, and (3) method is superior or at least equal to (1) method.

• Animal Bioscience
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• v.34 no.4
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• pp.489-498
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• 2021

Objective: Milk production is one of the most desirable traits in livestock. Recently, the toll-like receptor (TLR) has been identified as a candidate gene for milk traits in cows. So far, there is no information concerning the contribution of this gene in milk traits in sheep. This study was designed to investigate the TLR 4 gene polymorphisms in Barki ewes in Egypt and then correlate that with milk traits in order to identify potential single nucleotide polymorphisms (SNPs) for these traits in sheep. Methods: A part of the ovine TLR 4 gene was amplified in Barki ewes, to identify the SNPs. Consequently; Barki ewes were genotyped using polymerase chain reaction-single strand conformation polymorphism protocol. These genotypes were correlated with milk traits, which were the daily milk yield (DMY), protein percentage (PP), fat percentage (FP), lactose percentage, and total solid percentage (TSP). Results: Age and parity of the ewe had a significant effect (p<0.05 or p<0.01) on DMY, FP, and TSP. The direct sequencing identified a missense mutation located in the coding sequence of the gene (rs592076818; c.1710C>A) and was predicted to change the amino acid sequence of the resulted protein (p.Asn570Lys). The association analyses suggested a significant effect (p<0.05) of the TLR genotype on the FP and PP, while the DMY tended to be influenced as well (p = 0.07). Interestingly, the presence of the G allele tended to increase the DMY (+40.5 g/d) and significantly (p<0.05 or p<0.01) decreased the FP (-1.11%), PP (-1.21%), and TSP (-7.98%). Conclusion: The results of this study suggested the toll-like receptor 4 (TLR4) as a candidate gene to improve milk traits in sheep worldwide, which will enhance the ability to understand the genetic architecture of genes underlying SNPs that affect such traits.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.574-580
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• 2007

Full-length chloride intracellular channel protein 1 (CLIC1) is a member of the family of proteins related to bovine chloride intracellular channel p64. Mutations in the SEDL gene cause spondyloepiphyseal dysplasia tarda (SEDT), a rare X-linked chondrodysplasia. The link between the intracellular chloride channels and SEDL is an important step toward understanding their functional interplay. In the present study, CLIC1 protein was subcloned into the pGEX-KG vector and overexpressed in XL-1 blue cells. We developed a large-scale expression system composed of glutathione S-transferase (GST) fused with a 240-amino-acid CLIC1 protein in Escherichia coli. The soluble CLIC1 protein was successfully purified to homogeneity, and its purity, identity, activity and conformation were determined using SDS-PAGE, MALDI-MS, biophotometer and circular dichroism spectroscopic studies. The binding of both CLIC1 and SEDL proteins in vitro was detected by BIAcore biosensor and fluorescence measurements.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.250-258
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• 2004

An experiment was conducted to examine the effect of a high environmental temperature on the performance, conformation, and carcass characteristics of pigs and the influence of diet. Thirty-six three-way crossed castrated male pigs with average initial body weight of 50.4 kg were used in the experiment. The pig were allocated to the following treatments: two environmental temperatures (20 and $30^{\circ}C$)${\times}$three dietary energy levels (2,980, 3,300 and 3,600 kcal/kg)${\times}$three protein levels (12.8, 15.2 and 17.2%). Daily weight gain was lighter (p<0.01) and feed: gain ratio lower (p<0.05) in pigs at $30^{\circ}C$ than for pigs at $20^{\circ}C$ The pigs at $30^{\circ}C$ were significantly taller with deeper bodies (p<0.05) and significantly longer (p<0.05) both vertically horizontally in the planum nasal when kept at $30^{\circ}C$. The width of body and the circumference of the neck were greater (p<0.05) at $20^{\circ}C$. The lean meat of the loin, middle section, ham, and hind section were significantly greater (p<0.05) in pigs kept at $30^{\circ}C$ and the belly was significantly heavier. The total unsaturated free fatty acids were significantly higher (p<0.05) in the body fat of pigs kept at $20^{\circ}C$ than in that of pigs at $30^{\circ}C$. The results indicated that when pigs are given very restricted same amounts of feed, they may need less energy to maintain their body temperature under moderately high environmental temperature ($30^{\circ}C$); consequently, their performance is better than that of pigs under optimum environmental temperature. The results showed very clearly that weight gain of pigs increased with increasing of dietary protein and energy content. The increasing of dietary protein content seemed more significant when content increasing to 17.2% compared with the 12.8 and 15.2% protein content treatments. The increasing of dietary energy content was more significant when content increasing to 3,600 compared with the other low energy content treatments.

• Journal of the Korean Magnetic Resonance Society
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• v.1 no.2
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• pp.71-78
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• 1997

The magnetic anisotropy effects of peptide group in structured protein on proton chemical shift have been investigated using trialanine modeling. The structure dependent part of chemical shift of C${\alpha}$H of the second amino acid residue was assumed to come purely from the magnetic anisotropy effects of C=O and C-N bonds of peptide in the direct neighborhood and thus to be dependent on and $\psi$ angle of this dipeptide. A set of dipeptide models with different and $\psi$angles were generated and from these models the chemical shift values were calculated using known algorithm to emphasize the role of parameters used in the equation. Comparison of sets of different parameters resulted in an optimized parameters which could reproduce the statistical chemical shift values observed in proteins with respect ot the secondary conformation.