Correlations among mineral components, progressive calcification process and clinical symptoms of calcific tendonitis.

Objective: To establish the correlations among the mineral components, progressive calcification process and clinical symptoms of calcific tendonitis.

Methods: The morphology of the calcified deposits on the shoulders of 28 patients with calcific tendonitis was determined by high-resolution ultrasonography. The calcified deposit from each patient was aspirated and determined by the Fourier transform infrared and Raman microspectroscopies.

Mechanical compression affecting the thermal-induced conformational stability and denaturation temperature of human fibrinogen.

Thermal-induced conformational stability and changes in denaturation temperature of human fibrinogen (FBG) after different mechanical compressions were investigated by a simultaneous Fourier transform infrared microspectroscopy equipped with thermal analyzer (thermal FTIR microscopic system). The confocal Raman microspectroscopy was also applied to determine the thermal reversibility of solid FBG. FBG powder was pressed on one KBr pellet (1 KBr method) or sealed within two KBr pellets (2 KBr method) by different mechanical compressions.

Temperature effect on the structural stability, similarity, and reversibility of human serum albumin in different states.

In order to investigate the thermal stability of human serum albumin (HAS) in three different states (aqueous solution, cast film, and solid powder), Fourier transform infrared (FTIR) spectroscopy was applied to determine the protein secondary structural changes of these HSA samples under non-isothermal or isothermal condition. The structural similarity of HSA before and after thermal treatment was also studied to estimate the thermo-reversible property of the HSA in these different states. The results indicate that with the increase of temperature, the maximum peaks at 1652 and 1547 cm(-1) (alpha-helix) shifted to 1647 and 1542 cm(-1) (random coil), respectively.

pH- and thermal-dependent conformational transition of PGAIPG, a repeated hexapeptide sequence from tropoelastin.

The secondary structure of PGAIPG (Pro-Gly-Ala-IIe-Pro-Gly), a repeated hexapeptide of tropoelastin, in buffer solution of different pH was determined by using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The thermal-dependent structural change of PGAIPG in aqueous solution or in solid state was also examined by thermal FTIR microspectroscopy. The conformation of PGAIPG in aqueous solution exhibited a pH-dependent structural characterization.

Ethanol or/and captopril-induced precipitation and secondary conformational changes of human serum albumin.

We determined the secondary structure of solid-state native human serum albumin (HSA) and its precipitates induced by ethanol, captopril, or a captopril/ethanol mixture. A transmission Fourier transform infrared (FT-IR) microspectroscopy equipped with a thermal analyzer was used. The secondary structural composition of solid-state native HSA was 54% alpha-helices (1655 cm(-1)), 22% beta-turns (1679 cm(-1)), and 23% beta-sheets (1633 cm(-1)).

Pressure dependence of human fibrinogen correlated to the conformational alpha-helix to beta-sheet transition: an Fourier transform infrared study microspectroscopic study.

We used Fourier transform infrared (FTIR) microspectroscopy to investigate pressure-induced conformational changes in secondary structure of fibrinogen (FBG). Solid state FBG was compressed on a KBr pellet (1KBr method) or between two KBr pellets (2KBr method). The peak positions of the original and second-derivative ir spectra of compressed FBG samples prepared by the 1KBr method were similar to FBG sample without pressure.

Effect of ethanol or/and captopril on the secondary structure of human serum albumin before and after protein binding.

The attenuated total reflection/Fourier transform infrared technique has been utilized to characterize secondary structural changes in human serum albumin (HSA) before and after protein binding via incubation of HSA in different concentrations of ethanol, captopril or ethanol/captopril mixture. The results indicate that ethanol induced a transition from beta-sheet to an alpha-helical structure and promoted conversion of intramolecular hydrogen-bonded beta-sheet to intermolecular hydrogen-bonded beta-sheet. In contrast, captopril or captopril/ethanol mixture induced conversion of intramolecular hydrogen-bonded beta-sheet to intermolecular hydrogen-bonded beta-sheet and resulted in exposure of the aromatic side-chain groups in the unfolding conformation of HSA.

Fourier transform IR attenuated total reflectance spectroscopy studies of cysteine-induced changes in secondary conformations of bovine serum albumin after UV-B irradiation.

Fourier transform IR spectroscopy equipped with attenuated total reflection was used to investigate the cysteine-induced alteration of the protein secondary structure of bovine serum albumin (BSA) in aqueous solution before and after UV-B irradiation. Several amino acids were also studied. The results indicate the unchanged IR spectra of BSA coincubated with amino acids, except cysteine, did not change after 72-h UV-B irradiation.

Secondary conformations and temperature effect on structural transformation of amyloid beta (1-28), (1-40) and (1-42) peptides.

Secondary structure of three amyloid b-peptides [A beta(1-28), A beta(1-40) and A beta(1-42)] in the solid state was respectively determined by Fourier transform infrared (FT-IR) microspectroscopy. Their thermal-dependent structural transformation were also investigated by FT-IR microspectroscopy equipped with a thermal analyzer. The present result demonstrates that the solid-state A beta(1-28), A beta(1-40) and A beta(1-42) peptides showed a significant IR spectral difference in the amide I and II bands.

Transformation of metastable forms of acetaminophen studied by thermal Fourier transform infrared (FT-IR) microspectroscopy.

A novel Fourier transform infrared (FT-IR) microspectroscopy equipped with a micro hot stage (thermal FT-IR microscopic system) was used to quickly study the phase transformation of acetaminophen polymorphs by a one-step process. Acetaminophen was sealed in KBr disc on the first and second heating processes under this system. The results indicate that the contour IR profile of form I acetaminophen in the first heating process changed dramatically only near 165 degrees C, but in the re-heating process exhibited a considerable alteration in peak intensity, band width and position near the temperatures at 85, 118 and 153 degrees C.

Pressure-induced transformation of alpha-helix to beta-sheet in the secondary structures of amyloid beta (1-40) peptide exacerbated by temperature.

The effect of pressure on the conformational structure of amyloid beta (1-40) peptide (A beta(1-40)), exacerbated with or without temperature, was determined by Fourier transform infrared (FT-IR) microspectroscopy. The result indicates the shift of the maximum peak of amide I band of intact solid A beta(1-40) from 1655 cm(-1) (alpha-helix) to 1647-1643 cm(-1) (random coil) with the increase of the mechanical pressure. A new peak at 1634 cm(-1) assigned to beta-antiparallel sheet structure was also evident.