• Korea-Australia Rheology Journal
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• v.21 no.2
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• pp.103-108
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• 2009

Hemorheological properties are easily modified by glucose-induced oxidation and glycation. Carnosine, a naturally occurring dipeptide ($\beta$-alanyl-LFull-size image-histidine), has been recently proposed to act as an antioxidant as well as a free-radical scavenger. In the present study, we investigate its protective and rejuvenating effects in erythrocytes that are exposed to glucose-rich plasma. Erythrocytes that were incubated in glucose solutions were treated with different concentrations of carnosine and for different incubation times. Their hemorheological alterations were examined. The results reveal that the presence of carnosine effectively prevented these rheological alterations in a concentration-dependent manner in glucose-rich media. It is proposed that moderate concentrations of carnosine might be further explored as potential therapeutic agents for pathologies that involve hemorheological modification.

• The Korean Journal of Food And Nutrition
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• v.6 no.2
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• pp.73-80
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• 1993

In order to examine food components of coho salmon and rainbow-trout, We analyzed the composition of protein, amino acids and total lipids. The coho salmon muscle contained about 19.3% of protein with the composition of 29.9% in sarcoplasmic protein, 56.3oA in myofibrillar protein 12.5% alkali soluble protein and 2.6% in stroma. Those of rainbow-trout contained 34.1%, 56.4%, 8.3% and 2.9%, respectively. The sarcoplasmic and myofibrillar protein were composed of 13 subunits in coho salmon, and 16 and 15 subunits in rainbow-trout. Judging from the contents of essential amino acids, both muscle proteins were complete proteins. The most remarkable feature of free amino acids was that a large amount of dipeptide anserine was present with fairly lower levels of 1 methyl histidine, taurine, histidine, alanine and glycine in both muscle extracts. The total fatty acids of coho salmon was composed of 31.49% polyenes, 43.79% monoenes and 24.73% saturates. The composition of total fatty acid of coho salmon muscle was not different from that of rainbow-trout muscle.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.29-30
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• 2006

The synthesis of dendritic dipeptides $(4-3,4-3,5)12G2-CH_{2}-Boc-_{L}-Tyr-X-OMe\;where\;X\;=\;Gly,\;_{L}-Val,\;_{L}-Leu,\;_{L}-Ile,\;_{L}-Phe$, and L-Pro will be discussed. Their self-assembly in bulk and in solution and the structural and retrostructural analysis of their periodic assemblies will be compared to that of the previously reported and currently reinvestigated dendritic dipeptide with $X=_{L}-Ala$. All dendritic dipeptides containing as X nonpolar ${\alpha}-amino$ acids self-assemble into helical porous columns. The principles via which the aliphatic and aromatic substituents of X program the structure of the helical pores indicate synthetic pathways to helical pores with bioinspired functions based on artificial nonpolar ${\alpha}-amino$ acids will be discussed.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.798-804
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• 2014

We present calculations for diglycine - $(H_2O)_n$ (n = 0-3) to examine the effects of microsolvating water on the relative stability of the zwitterionic vs. canonical forms of the dipeptide. We calculate the structures, energies and Gibbs free energies of the conformers at wB97XD/6-311++G** and MP2/aug-cc-pvdz levels of theory level of theory. We predict that microsolvation by up to three water molecules does not give thermodynamic stability of the zwitterion relative to the canonical forms. Our calculations also suggest that zwitterionic diglycine - $(H_2O)_3$ is not stable kinetically in low temperature gas phase environment.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2000.11a
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• pp.28-31
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• 2000

We describe a hidden Markov model, HMMTIR, for general protein sequence based on the I-sites library of sequence-structure motifs. Unlike the linear HMMs used to model individual protein families, HMMSTR has a highly branched topology and captures recurrent local features of protein sequences and structures that transcend protein family boundaries. The model extends the I-sites library by describing the adjacencies of different sequence-structure motifs as observed in the database, and achieves a great reduction in parameters by representing overlapping motifs in a much more compact form. The HMM attributes a considerably higher probability to coding sequence than does an equivalent dipeptide model, predicts secondary structure with an accuracy of 74.6% and backbone torsion angles better than any previously reported method, and predicts the structural context of beta strands and turns with an accuracy that should be useful for tertiary structure prediction. HMMSTR has been incorporated into a public, fully-automated protein structure prediction server.

• Journal of the Korean Chemical Society
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• v.14 no.2
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• pp.161-168
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• 1970

In order to obtain the more effective evidence, supporting the hypothesis which have been previously described by former report that pepsin (EC 3.4. 4.1) forms a hydrophobic bond with the nonpolar side chain of its substrate, the inhibitory effect of carboxylic acids(from formic acid to iso-butyric acid) on the activity of pepsin to the synthetic dipeptide, N-Carbobenzoxy-L-glutamyl-L-tyrosine, was discussed. The kinetic study showed that the inhibition by carboxylic acids was competitive. The Kidecreased with increasing size of the inhibitor molecule. The $-{\Delta}F^{\circ}$increased linearly with increasing number of carbon atoms in the hydrocarbon chain of the inhibitor. It was confirmed that the hydrophobic bond between more than one side chain of amino acid residues(phenylalanine) in the binding region of the active center of pepsin and the side chain of amino acid residues in the substrate was formed as the first step of its enzymic mechanism. The inhibitory effect of carboxylic acids was due to the competition of the hydrocarbon group of the carboxylic acids with the side chain of the substrate for the hydrophobic binding site(the side chain of phenylalanine) of the pepsin.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.90-91
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• 2002

The angiotensin converting enzyme (ACE) generates the powerful vasoconstrictor angiotensin II by removing the C-terminal dipeptide from the precursor decapeptide angiotensin I (1). The enzyme also inactivates the vasodilator bradykinin (2). There have been many studies on ACE inhibitory substances as functional in food, and ACE inhibitory peptides were isolated (3-5). (omitted)

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.204-204
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• 2011

During past decades, several types of peptide-based scaffolds, ranging from simple aromatic dipeptide to small protein fragments, have been studied to understand the underlying mechanism and mimic to create artificial nano/microstructures. However, a limited number of design principles have still been reported in peptidic scaffolds allowing well-defined self-assembled structure formation, presumably due to the intrinsic large conformational flexibility of natural peptides. In this presentation, we report the first example of highly homogeneous, well-defined and finite architectures by the ${\beta}$-peptide self-assembly.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.135.2-135
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• 2003

Angiotensin converting enzyme (ACE) converts angiotensin I into angiotensin II by cleaving C-terminal dipeptide of angiotensin I and inactivates bradykinin. ACE inhibitors have been screened from various food sources since the inhibitors decrease blood pressure. Therefore, in this study, an ACE inhibitor was isolated and purified from squid ink using membrane filtration, gel permeation chromatography, normal phase HPLC, and fast protein liquid chromatography. The purified inhibitor was identified to be a molecular mass of 294 by mass spectrometry, and to have IC$\sub$50/ value of 4.9 $\mu\textrm{g}$/mL.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.989-992
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• 2005

Dynamic kinetic resolution of $\alpha$-bromo carboxylic acid derivatives in nucleophilic substitution with chiral $\alpha$-amino ester nucleophiles in the presence of TBAI and DIEA has been investigated for stereoselective syntheses of 1,1'-iminodicarboxylic acid derivatives. Nucleophilic substitutions with various chiral $\alpha$-amino esters gave iminodiacetates 2-8 with stereoselectivities up to 87 : 13 dr. Also, the reactions of N-($\alpha$-bromo-$\alpha$-phenylacetyl)-L-alanine methyl ester with L-alanine, D-alanine and glycine methyl ester nucleophiles afforded N-carboxyalkyl dipeptide analogues 10-12 up to 90 : 10 dr.