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Analysis of the interaction between human plasma fibronectin and gelatin by affinity electrophoresis
The interaction between human plasma fibronectin and gelatin was analyzed by affinity electrophoresis, in which the fibronectin was subjected to electrophoresis in a 4% polyacrylamide gel in the presence and absence of gelatin, as an affinity ligand, and the fibronectin band was stained by an immunoblotting method. The apparent dissociation constants (Kd) of fibronectin for gelatin were calculated from affinity plots based on the original affinity equation at different pHs, urea concentrations, and temperatures. The fibronectin exhibited much lower affinity in the presence of urea. The Kds at 37 degrees C were 1.49 X 10(-7) M, 2.50 X 10(-6) M, and 3.58 X 10(-6) M with 2 M, 3 M, and 4 M urea, respectively. The van't Hoff plots of Kd values against absolute temperature (T) showed that the value of log Kd decreased in proportion to the increase in the value of 1/T within the range of 15-50 degrees C. The standard enthalpy, the standard free energy change at 37 degrees C, and the entropy change at 37 degrees C for association were calculated to be -124.7 kJ/mol, -33.23 kJ/mol, and -295.1 J/mol/deg, respectively. These results suggest that a hydrophilic interaction, such as hydrogen bond or van der Waals interaction, plays an important role in the binding of plasma fibronectin to gelatin. 相似文献
2.
Ito S. Ishikawa H. Miura T. Takasago K. Endo A. Torizuka K. 《Applied physics. B, Lasers and optics》2003,76(5):497-503
We present a 7-TW Ti:sapphire laser system operating at 50 Hz for laser Compton femtosecond X-ray generation. This laser system
delivers 8.4 W of average output power at a repetition rate of 50 Hz with a pulse width of 24 fs. It demonstrates successful
management using a dynamically stable resonator in the regenerative amplifier and compensation for thermal lensing by a convex
mirror in a ring-type four-pass power amplifier. We also present the results of closed-loop corrections for distorted wavefronts
of amplified and compressed laser pulses, using an adaptive optical system consisting of a Shack–Hartmann-type wavefront sensor
and a deformable mirror. This closed-loop correction results in dramatic improvements, reducing wavefront distortions below
0.05 λ rms.
Received: 31 October 2002 / Revised version: 3 March 2003 / Published online: 5 May 2003
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ID="*"Corresponding author. Fax: +81-298/61-3349, E-mail: ito@festa.or.jp 相似文献
3.
T. Miura H. Nagaoka K. Takasago K. Kobayashi A. Endo K. Torizuka M. Washio F. Kannari 《Applied physics. B, Lasers and optics》2002,75(1):19-23
Two mode-locked Ti:sapphire lasers of different wavelengths were precisely synchronized by a simple feedback system employing
sum-frequency generation (cross correlation). When the timing error exceeded the pulse duration, the periodic bunch of the
sum-frequency pulse was used for rough timing adjustment. Using cross correlation with a stretched pulse, we struck a balance
between wide locking range and sensitive timing detection. When the two lasers were well-synchronized, we obtained a continuous
cross-correlation pulse train for 3 min. The holding time of the laser synchronization was extended to over one hour by adding
a motorized stage to the PZT-mounted cavity mirror. We estimated the rms timing jitter between the two lasers by a scanning
cross-correlation measurement. We confirmed that the rms timing jitter of the two lasers during 1.8 s was 28 fs.
Received: 30 January 2002 / Revised version: 14 June 2002 / Published online: 8 August 2002 相似文献
4.
Poly(l‐lactic acid)‐modified silica stationary phase for reversed‐phase and hydrophilic interaction liquid chromatography
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Kaname Ohyama Shizuka Takasago Naoya Kishikawa Naotaka Kuroda 《Journal of separation science》2015,38(5):720-723
Poly(l ‐lactic acid) is a linear aliphatic thermoplastic polyester that can be produced from renewable resources. A poly(l ‐lactic acid)‐modified silica stationary phase was newly prepared by amide bond reaction between amino groups on aminopropyl silica and carboxylic acid groups at the end of the poly(l ‐lactic acid) chain. The poly(l ‐lactic acid)‐silica column was characterized in reversed‐phase liquid chromatography and hydrophilic interaction liquid chromatography with the use of different mobile phase compositions. The poly(l ‐lactic acid)‐silica column was found to work in both modes, and the retention of test compounds depending on acetonitrile content exhibited “U‐shaped” curves, which was an indicator of reversed‐phase liquid chromatography/hydrophilic interaction liquid chromatography mixed‐mode retention behavior. In addition, carbonyl groups included into the poly(l ‐lactic acid) backbone work as an electron‐accepting group toward a polycyclic aromatic hydrocarbon and provide π–π interactions. 相似文献
5.
A new method of type III collagen analysis by uninterrupted sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) combined with immunoblotting was developed. The electrophoresis was carried out with gels containing 4 M urea. A negatively charged reducing agent, thioglycolic acid, was added to the running buffer of the cathodic reservoir between 15 and 20 min after Bromphenol Blue (BPB) migrated to the top of the separating gel, to reduce interchain disulfide binding of the collagen. The polymorphic type III collagens, i.e., an alpha-chain derived from a trimer [alpha 1(III)]3 with interchain disulfide bonds but without covalent cross-links, alpha 1(III), a beta-chain with covalent cross-links, beta(III), or an alpha-chain released from a trimer without reduction of the disulfide bonds, alpha*1(III), were identified by immunostaining and quantified by densitometry. Using this method, changes in collagen type III polymorphism with aging were examined in the aorta, brachial artery, and skin of rats. The total quantity of collagen type III decreased with aging in all tissues. beta(III) was the major component in the aorta and brachial artery, but alpha 1(III) was the major component in the skin. With increasing age from 3 to 60 weeks, the ratio of beta(III) to alpha 1(III), which is correlated with the extent of covalent cross-linking, showed a steep increase in the aorta but only a slight increase in the skin and it remained almost constant in the brachial artery.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
6.
M. Yorozu J. Yang Y. Okada T. Yanagida F. Sakai K. Takasago S. Ito A. Endo 《Applied physics. B, Lasers and optics》2002,74(4-5):327-331
A short-pulse X-ray-generation experiment was performed by Compton scattering through interaction between a 3-ps electron
beam and 100-fs laser photons in a 90° scattering configuration. The observed X-ray intensity was typically 3×104 photons/pulse and roughly matched the theoretically expected intensity. The X-ray energy and pulse duration were estimated
theoretically to be 2.3 keV and 280 fs from the observed electron- and laser-beam parameters. The fluctuation of the X-ray
output was measured as 25% (rms) during a 30-min operation. The fluctuation was expressed as a function of the fluctuation
of the timing between the electron and laser beams. The measured fluctuation of the X-rays was approximately consistent with
that caused by the fluctuation of the timing between the beams.
Received: 19 November 2001 / Revised version: 23 January 2002 / Published online: 14 March 2002 相似文献
7.
T. Imahoko K. Takasago M. Kamata J. Sakuma T. Sumiyoshi H. Sekita M. Obara 《Applied physics. B, Lasers and optics》2007,89(2-3):217-222
We have developed a pulsed Yb:YAG thin disk green laser for pumping a 100 kHz and 10 W femtosecond laser. We optimized numerically
and experimentally the open duration of the acousto-optic (AO) Q-switcher and the internal SHG method, generating stable output
energy at a 100 kHz repetition rate. We demonstrated a 515 nm output power of over 80 W with a pulse-to-pulse stability of
less than 1% RMS with an LD power to green power conversion efficiency of 24%. With the developed green laser, we obtained
16 W of a Ti:sapphire laser in a cavity dumped mode.
PACS 42.55.Xi; 42.60.Gd; 42.60.By; 42.65.-k; 42.65.Re 相似文献
8.
We measure the timing error of femtosecond pulses amplified by a Ti:sapphire regenerative amplifier at a 1-kHz repetition rate by use of a modified cross-correlation technique. Linearly frequency-chirped amplified pulses are frequency mixed with transform-limited oscillator pulses. A shift in the sum frequency corresponds to the timing error of each amplified pulse relative to the oscillator pulses. The timing error was measured every 6 ms with approximately 1-fs resolution over a measurable range of 400 fs. 相似文献
9.
T. Imahoko K. Takasago T. Sumiyoshi H. Sekita K. Takahashi M. Obara 《Applied physics. B, Lasers and optics》2007,87(4):629-634
We have developed a 6–12 μm mid-infrared (MIR) femtosecond laser source for glyco-protein structure analysis. The MIR femtosecond
laser pulses are generated by a differential frequency generation (DFG) configuration with a combination of Ti:sapphire based
regeneratively amplified femtosecond laser pulses (780 nm, 160 fs, 1 mJ) and a β-BaB2O4 (BBO) based optical parametric amplifier (OPA). The MIR pulse energy exceeds 4.5 μJ, where a glyco-protein molecule has resonant
absorption lines due to the vibrational–rotational transitions. The pulse width is estimated to be less than 1 ps according
to the cross correlation measurement between the two OPA output pulses. Using the MIR femtosecond laser pulses, we demonstrated
photo-dissociation of the sialyl Lewis X (sLeX) proton added ion, which is the first time to the best of our knowledge.
PACS 42.65.Re; 42.62.-b; 42.60.-b; 42.65.-k; 87.50 相似文献
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