Near-infrared analysis of protein secondary structure in aqueous solutions and freeze-dried solids

Izutsu, Ken‐ichi; Fujimaki, Yasuto; Kuwabara, Akihide; Hiyama, Yukio; Yomota, Chikako; Aoyagi, Nobuo

doi:10.1002/jps.20580

Cited by 63 publications

(54 citation statements)

References 37 publications

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“…The spectrum is dominated by combination bands in the region 5,200-4,000 cm −1 , similar to bands found for other proteins (37). Most of these bands have been tentatively assigned to combinations of amide I, amide II, amide III, amide A, amide B and C-H stretching bands (38,39).…”

Section: Near Infrared Spectroscopysupporting

confidence: 68%

Multivariate Analysis of Phenol in Freeze-Dried and Spray-Dried Insulin Formulations by NIR and FTIR

et al. 2011

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Dehydration is a commonly used method to stabilise protein formulations. Upon dehydration, there is a significant risk the composition of the formulation will change especially if the protein formulation contains volatile compounds. Phenol is often used as excipient in insulin formulations, stabilising the insulin hexamer by changing the secondary structure. We have previously shown that it is possible to maintain this structural change after drying. The aim of this study was to evaluate the residual phenol content in spray-dried and freeze-dried insulin formulations by Fourier transform infrared (FTIR) spectroscopy and near infrared (NIR) spectroscopy using multivariate data analysis. A principal component analysis (PCA) and partial least squares (PLS) projections were used to analyse spectral data. After drying, there was a difference between the two drying methods in the phenol/insulin ratio and the water content of the dried samples. The spray-dried samples contained more water and less phenol compared with the freeze-dried samples. For the FTIR spectra, the best model used one PLS component to describe the phenol/insulin ratio in the powders, and was based on the second derivative pre-treated spectra in the 850-650 cm −1 region. The best PLS model based on the NIR spectra utilised three PLS components to describe the phenol/insulin ratio and was based on the standard normal variate transformed spectra in the 6,200-5,800 cm −1 region. The root mean square error of cross validation was 0.69% and 0.60% (w/w) for the models based on the FTIR and NIR spectra, respectively. In general, both methods were suitable for phenol quantification in dried phenol/insulin samples.

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Section: Near Infrared Spectroscopysupporting

confidence: 68%

Multivariate Analysis of Phenol in Freeze-Dried and Spray-Dried Insulin Formulations by NIR and FTIR

et al. 2011

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“…The NIR spectrum of bovine serum albumin (BSA) [Fig. 5] is dominated by spectral features attributed to the alpha-helical structures found within the protein (Izutsu et al, 2006). These peaks, particularly 4090, 4370 and 4615 cm −1 were shifted or of lower intensity in the collagen spectra.…”

Section: Discussionmentioning

confidence: 99%

Assessment of hyaline cartilage matrix composition using near infrared spectroscopy

2014

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Changes in the composition of the extracellular matrix (ECM) are characteristic of injury or disease in cartilage tissue. Various imaging modalities and biochemical techniques have been used to assess the changes in cartilage tissue but lack adequate sensitivity, or in the case of biochemical techniques, result in destruction of the sample. Fourier transform near infrared (FT-NIR) spectroscopy has shown promise for the study of cartilage composition. In the current study NIR spectroscopy was used to identify the contributions of individual components of cartilage in the NIR spectra by assessment of the major cartilage components, collagen and chondroitin sulfate, in pure component mixtures. The NIR spectra were obtained using homogenous pellets made by dilution with potassium bromide. A partial least squares (PLS) model was calculated to predict composition in bovine cartilage samples. Characteristic absorbance peaks between 4000 and 5000 cm(-1) could be attributed to components of cartilage, i.e. collagen and chondroitin sulfate. Prediction of the amount of collagen and chondroitin sulfate in tissues was possible within 8% (w/dw) of values obtained by gold standard biochemical assessment. These results support the use of NIR spectroscopy for in vitro and in vivo applications to assess matrix composition of cartilage tissues, especially when tissue destruction should be avoided.

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“…For example, certain (though not all) dehydrins were shown to be disordered under native conditions (Eom et al, 1996;Lisse et al, 1996;Soulages et al, 2003;Mouillon et al, 2006). Nearinfrared spectroscopy analysis of a number of proteins of similar M r range with ASR1 suggested that freezedried proteins mostly maintain spectral characteristics of native structure (Izutsu et al, 2006). Thus, the freeze drying step in the preparation of ASR1 is not likely to induce any major structural changes.…”

Section: Asr1 As Intrinsically Unstructured Proteinmentioning

confidence: 99%

Desiccation and Zinc Binding Induce Transition of Tomato Abscisic Acid Stress Ripening 1, a Water Stress- and Salt Stress-Regulated Plant-Specific Protein, from Unfolded to Folded State

et al. 2006

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Abscisic acid stress ripening 1 (ASR1) is a low molecular weight plant-specific protein encoded by an abiotic stress-regulated gene. Overexpression of ASR1 in transgenic plants increases their salt tolerance. The ASR1 protein possesses a zinc-dependent DNA-binding activity. The DNA-binding site was mapped to the central part of the polypeptide using truncated forms of the protein. Two additional zinc-binding sites were shown to be localized at the amino terminus of the polypeptide. ASR1 protein is presumed to be an intrinsically unstructured protein using a number of prediction algorithms. The degree of order of ASR1 was determined experimentally using nontagged recombinant protein expressed in Escherichia coli and purified to homogeneity. Purified ASR1 was shown to be unfolded using dynamic light scattering, gel filtration, microcalorimetry, circular dichroism, and Fourier transform infrared spectrometry. The protein was shown to be monomeric by analytical ultracentrifugation. Addition of zinc ions resulted in a global change in ASR1 structure from monomer to homodimer. Upon binding of zinc ions, the protein becomes ordered as shown by Fourier transform infrared spectrometry and microcalorimetry, concomitant with dimerization. Tomato (Solanum lycopersicum) leaf soluble ASR1 is unstructured in the absence of added zinc and gains structure upon binding of the metal ion. The effect of zinc binding on ASR1 folding and dimerization is discussed.

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Near-infrared analysis of protein secondary structure in aqueous solutions and freeze-dried solids

Cited by 63 publications

References 37 publications

Multivariate Analysis of Phenol in Freeze-Dried and Spray-Dried Insulin Formulations by NIR and FTIR

Multivariate Analysis of Phenol in Freeze-Dried and Spray-Dried Insulin Formulations by NIR and FTIR

Assessment of hyaline cartilage matrix composition using near infrared spectroscopy

Desiccation and Zinc Binding Induce Transition of Tomato Abscisic Acid Stress Ripening 1, a Water Stress- and Salt Stress-Regulated Plant-Specific Protein, from Unfolded to Folded State

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