• Analytical Science and Technology
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• v.13 no.4
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• pp.494-503
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• 2000

A 21-residue peptide corresponding to amino acids 84-104 of $p16^{INK4A}$, the tumor suppressor, has been synthesized and its structure was studied by Circular Dichroism, $^1H$ NMR spectroscopy and molecular modeling. A p16-derived peptide (84-104 amino acids) forming stable complex with CDK4 and CDK6 inhibits the ability of CDK4/6 to phosphorylate pRb in vitro, and blocks cell-cycle progression through G1/S phase as shown in the function of the full-length p16. Its NMR spectral data including NOEs, $^3J_{NH-H{\alpha}}$ coupling constants, $C_{\alpha}H$ chemical shift, the average amplitude of amide chemical shift oscillation and temperature coefficients indicate that the secondary structure of a p16-derived peptide is similar to that of the same region of full-length p16, which consists of helix-turn-helix structure. The 3-D distance geometry structure based on NOE-hased distance and torsion angle restraints is characterized by ${\gamma}$-turn conformation between residues $Gly^{89}-Leu^{91}$(${\varphi}_{i+1}=-79.8^{\circ}$, ${\varphi}_{i+1}=60.2^{\circ}$) as evidenced in a single crystal structure for the corresponding region of p18 or p19, but is undefined at both the N and C termini. This compact and rigid ${\gamma}$-turn region is considered to stabilize the structure of p16-derived peptide and serve as a site recognizing cyelin dependent kinase, and this well-defined ${\gamma}$-turn structure could be utilized for the design of anti-cancer drug candidates.

• Current Research on Agriculture and Life Sciences
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• v.26
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• pp.23-30
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• 2008

In this paper, when the silk fabric was modified by ethylene cyanohydrine, the reaction mechanism between both was studied at various treatment conditions such as curing temperatures and times, ethylene cyanohydrin concentrations and $ZnCl_2$ concentrations. Through the FT-IR and DSC analyses of the treated silk fabrics, we found the results as follows : It was observed in FT-IR analysis of the treated silk fabrics that the -OH characteristic peak($3,450cm^{-1}$)position and shape were all changed when drying and curing treatment conditions were at $80^{\circ}C$ for 3 minute and $110^{\circ}C$ for 2.5 minute, and the concentration of the $ZnCl_2$ was 0.1%. It indicated that the -OH group of the silk participated in the reaction between the silk fabric and ethylene cyanohydrin. From the DSC analysis, it was found that the pyrolysis temperatures of the treated silk fabrics by ethylene cyanohydrin which was processed in the same condition, were all increased from $311^{\circ}C$ to ab. $320^{\circ}C$. From the FT-IR analyses of the silk fabrics treated by ethylene cyanohydrin at the various concentrations of $ZnCl_2$, it was found that the -OH characteristic peaks($3,450cm^{-1}$) were similar to the nontreated one except that of the fabric treated at the $ZnCl_2$ conconcentration of 0.8% when drying and curing treatment conditions were at $80^{\circ}C$ for 3minute and $110^{\circ}C$ for 2.5 minute, and the concentration of the ethylene cyanohydrin was 5%. In the case of the $ZnCl_2$ concentration of 0.8% solution, a lot of change were observed in peak. From the DSC analysis of the treated silk fabrics which was processed in the same condition, it was showed that the pyrolysis temperatures of treated silk fabric were all increased from $311^{\circ}C$ to ab. $320^{\circ}C$, which was no relation with the concentration of $ZnCl_2$.

• Journal of the Korean Vacuum Society
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• v.15 no.6
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• pp.563-575
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• 2006

Ti(C,N) films are synthesized by pulsed DC plasma enhanced chemical vapor deposition (PEMOCVD) using metal-organic compounds of tetrakis diethylamide titanium at $200-300^{\circ}C$. To compare plasma parameter, in this study, $H_2$ and $He/H_2$ gases are used as carrier gas. The effect of $N_2\;and\;NH_3$ gases as reactive gas is also evaluated in reduction of C content of the films. Radical formation and ionization behaviors in plasma are analyzed in-situ by optical emission spectroscopy (OES) at various pulsed bias voltages and gas species. He and $H_2$ mixture is very effective in enhancing ionization of radicals, especially for the $N_2$. Ammonia $(NH_3)$ gas also highly reduces the formation of CN radical, thereby decreasing C content of Ti(C, N) films in a great deal. The microhardness of film is obtained to be $1,250\;Hk_{0.01}\;to\;1,760\;Hk_{0.01}$ depending on gas species and bias voltage. Higher hardness can be obtained under the conditions of $H_2\;and\;N_2$ gases as well as bias voltage of 600 V. Hf(C, N) films were also obtained by pulsed DC PEMOCYB from tetrakis diethyl-amide hafnium and $N_2/He-H_2$ mixture. The depositions were carried out at temperature of below $300^{\circ}C$, total chamber pressure of 1 Torr and varying the deposition parameters. Influences of the nitrogen contents in the plasma decreased the growth rate and attributed to amorphous components, to the high carbon content of the film. In XRD analysis the domain lattice plain was (111) direction and the maximum microhardness was observed to be $2,460\;Hk_{0.025}$ for a Hf(C,N) film grown under -600 V and 0.1 flow rate of nitrogen. The optical emission spectra measured during PEMOCVD processes of Hf(C, N) film growth were also discussed. $N_2,\;N_2^+$, H, He, CH, CN radicals and metal species(Hf) were detected and CH, CN radicals that make an important role of total PEMOCVD process increased carbon content.