• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.7
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• pp.911-919
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• 1998

부탄테트라카르복실 산을 이용한 면직물의 DP 가공에서 가장 효과적인 촉매로 알려진 sodium hypophosphite(SHP)를 대체하기 위하여 carbodiimide 촉매의 효과를 알아보았다. Carbo야-imide 촉매로는 cyanamide(CY), dicyandiamide(DCY)와 disodium cyanamide(DSC)를 사용하였다. DCY와 DSC가 일반적으로 CY보다 좋은 방추도와 방축도 등을 보였고 또한 독성이 낮고 저장시 안정도 등이 우수하므로 산업적인 응용이 가능하다. 필요한 방추도와 물리적성질의 균형을 위해서 가공욕의 pH 조절이 가장 중요한 인자로 나타났다. 촉매존재시에 면과 부탄테트라카르복실산의 에스터화 가교 반응 메커니즘을 제아하였다. 또한 황화 염료로 염색된 염색포에 대한 가공 효과 분석시 carbodiimide 촉매가 SHP 보다 대체로 작은 색상 변화를 유발시켰다. 이러한 연구 결과는 부양화와 여러 염료의 색상 변화를 유발시키는 SHP를 사용하지 않고 부탄테트라카르복실 산과 carbodiimide 촉매를 이용한 무포름알데히드, 무인 가공제의 면직물 DP 가공의 가능성을 보여 주고 있다.

• BMB Reports
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• v.29 no.3
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• pp.215-220
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• 1996

A general procedure to quantitate the reaction of carbodiimides with carboxy groups of proteins is described. Pyridoxamine reacts with the o-acylisourea intermediate generated during the reaction of carboxyl residues with carbodiimides. The extent of the reaction is determined by measuring the spectroscopic properties, absorption and emission, of pyridoxyl residues covalently attached to the proteins. Resolved pig brain aspartate aminotransferase (apoenzyme), inactivated by 1-ethyl-3-(3-dimethylamino propyl) carbodiimide, reacts with $[^{3}H]pyridoxamine$. After trypsin digestion, one peptide labeled with radioactive pyridoxyl was separated by reverse phase HPLC.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.121-128
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• 2006

The purified xylanase from Bacillus alcalophilus AX2000 was modified with various chemical modifiers to determine amino acid residues in the active site of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results suggested that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and N-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.416-421
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• 1998

A carboxyl group modifier, l-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) was used to study the interactions between three components of toluene dioxygenase (TDO) from Pseudomonas putida FI. $Ferredoxin_{TOL}$ activity was increased by the treatment with EDC; however, the activity was rapidly declined in the prolonged incubation. In covalent cross-linking experiments with EDC, $Ferredoxin_{TOL}$ made a one-to-one complex with $Reductase_{TOL}$ or the large subunit of $ISP_{TOL}$. These results provide evidence for the involvement of electrostatic interactions in the TDO electron transfer system.

• Bulletin of the Korean Chemical Society
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• v.16 no.11
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• pp.1037-1042
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• 1995

The reaction of acetophenone 1-ureidoethylidenehydrazones 6 with a mixture of triphenylphosphine, carbon tetrachloride, and triethylamine in dichloromethane provides a general route to 1-(1-phenylethenyl)-5-(N-substituted amino)-1,2,4-triazoles 11 via the electrocyclization of the expected azino carbodiimide intermediates 9 to give the resonance stabilized azomethine imine 10a followed by a proton abstraction from the methyl group by amide anion. However, the same reaction of benzaldehyde 1-ureidoethylidenehydrazones 5 was unsuccessful. Under the same conditions, the reactions of benzaldehyde 1-N-acylureidoethylidenehydrazones 7 or acetophenone 1-N-acylureidoethylidenehydrazones 8 afforded 4H-1,2,4-triazolo[1,5-c][1,3,5]oxadiazines 16 or 17 via the zwitterionic species 15, or a [4+2] intramolecular cycloaddition from the carbodiimide intermediates 14, respectively.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.633-640
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• 2005

The purified xylanase from Bacillus pumilus TX703 was modified with various chemical modifiers to determine the active sites of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results assumed that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and W-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.

• Korea Journal of Cosmetic Science
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• v.2 no.1
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• pp.11-19
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• 2020

The aim of this study is to investigate the effect of various pentapeptides on hair repair depending on the characteristics of comprising amino acids using crosslinking agents in hair. Total ten peptides were synthesized with two kinds of amino acids respectively, of which were previously categorized according to R group of the amino acids contributing to the characteristic of each peptide: STTSS (Ser-Thr-Thr-Ser-Ser), LIILL (Leu-Ile-Ile-Leu-Leu), CMMCC (Cys-Met-Met-Cys-Cys), DEEDD (Asp-Glu-Glu-Asp-Asp), RKKRR (Arg-Lys-Lys-Arg-Arg), TAMRA-STTSS, TAMRA-LIILL, TAMRA-CMMCC, TAMRA-DEEDD, and TAMRA-RKKRR. Pentapeptide alone, or pentapeptides with crosslinking agents such as polymeric carbodiimide (PCI) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were treated to chemically damaged hair. Hair diameter and break strength (N = 40/case) were measured to calculate tensile strength of hair for computing hair repair ratio, and fluorescence yields (N = 20/case) were collected for hair treated with TAMRA-peptides. The tensile strength of hair treated with pentapeptides alone, or pentapeptides with cross-linking agents is consistent with the fluorescence yield from the microscope images of the cross-sectioned hair in vision and in numerical values. Pentapeptides consisting of hydrophobic amino acids (LIILL), amino acids with sulfur (CMMCC), and basic amino acids (RKKRR) increased the tensile strength in perm-damaged hair. Pentapeptides with no extra carboxyl/amine groups in R group of amino acids resulted in no significant differences in hair strength and fluorescence yield among hairs treated with alone and with crosslinkers. Pentapeptides with extra carboxyl groups or amine groups enabled further strengthening of hair due to increased bonds within the hair after carbodiimide coupling reaction. The hair repairs of pentapeptides with various amino acid sequences were studied using crosslinking. Depending on the physical characteristics of comprising amino acids, the restoration of damaged hair was observed with tensile strength of hair and fluorescence signals upon cross-sectioned hair in parallel to possibly understand the binding tendency of each pentapeptide within the hair.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.133-139
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• 2018

Chemically damaged hair is vulnerable to external stimuli in daily life due to the weakened physical properties of the hair strand itself. The purpose of this work was to determine whether chemical conjugation between hair keratin proteins restores tensile strength and thus results inpreventing further deterioration under repeated combing. A model damaged hair tress was produced by a typical perm-process. Then, it was internally crosslinked by the bifunctional crosslinker (3-aminopropyl)triethoxysilane (APTES), via both silane coupling and carbodiimide chemistry. Physical properties, including tensile strength, Young's modulus, and plateau stress, were measured to verify the effect of internal crosslinking, and the existence of crosslinking was verified by Fourier transform infrared (FT-IR) spectroscopy. The degrees of hair breakage and split ends were evaluated by repeated combing-drying tests. Physical properties of chemically damaged hair were restored by internal crosslinking. Successful crosslinking of APTES via both silane coupling and carbodiimide chemistry was verified by FT-IR spectra. Prevention of breakage and split ends after repeated combing with heat was observed. Human hair can be weakened by chemical damage including perm-processing, so restoring such properties is a major issue in the hair care industry. This work shows that internal crosslinking of damaged hair via chemical conjugation would be a potent method to restore the healthy hair.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1371-1374
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• 2012

• YAKHAK HOEJI
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• v.39 no.5
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• pp.569-571
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• 1995