Multivariate analysis of the association of bromocresol purple anion with bovine serum albumin

Nakamaru, Yoshiaki; Sato, Chuichiro

doi:10.1016/s0167-4838(97)00081-2

Cited by 7 publications

(3 citation statements)

References 25 publications

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“…We confirmed that lower dielectric media such as methanol induce a red shift in the spectrum of the deprotonated form of bromocresol purple (data not shown). It is also well-known that BCP binds to bovine serum albumin (BSA) with a substantial red shift and that the change in the BCP spectrum upon binding can be used to estimate the amount of BSA (37). Titrating the anionic form of BCP with BSA, the isosbestic point is at 598 nm, close to our estimated value of between 595 and 600 nm.…”

Section: Discussionsupporting

confidence: 77%

“…Titrating the anionic form of BCP with BSA, the isosbestic point is at 598 nm, close to our estimated value of between 595 and 600 nm. Moreover, the measured difference spectrum when BCP binds to BSA (37) has a striking quantitative similarity with panel E of Figure 3, and the absolute spectra of the free and bound forms correspond closely to the D 1 and D 2 spectra from our SVD analysis (Figure 7A) (37). The results of the extensive measurements on BCP binding to BSA (see also references in ref 37) fully support our interpretation of the nonproton part of the transient dye signal as binding to the I 2 form of PYP.…”

Section: Discussionsupporting

confidence: 65%

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Kinetics of Proton Uptake and Dye Binding by Photoactive Yellow Protein in Wild Type and in the E46Q and E46A Mutants

et al. 2002

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We studied the kinetics of proton uptake and release by photoactive yellow protein (PYP) from Ectothiorhodospira halophila in wild type and the E46Q and E46A mutants by transient absorption spectroscopy with the pH-indicator dyes bromocresol purple or cresol red in unbuffered solution. In parallel, we investigated the kinetics of chromophore protonation as monitored by the rise and decay of the blue-shifted state I(2) (lambda(max) = 355 nm). For wild type the proton uptake kinetics is synchronized with the fast phase of I(2) formation (tau = 500 micros at pH 6.2). The transient absorption signal from the dye also contains a slower component which is not due to dye deprotonation but is caused by dye binding to a hydrophobic patch that is transiently exposed in the structurally changed and partially unfolded I(2) intermediate. This conclusion is based on the wavelength, pH, and concentration dependence of the dye signal and on dye measurements in the presence of buffer. SVD analysis, moreover, indicates the presence of two components in the dye signal: protonation and dye binding. The dye binding has a rise time of about 4 ms and is coupled kinetically with a transition between two I(2) intermediates. In the mutant E46Q, which lacks the putative internal proton donor E46, the formation of I(2) is accelerated, but the proton uptake kinetics remains kinetically coupled to the fast phase of I(2) formation (tau = 100 micros at pH 6.3). For this mutant the protein conformational change, as monitored by the dye binding, occurs with about the same time constant as in wild type but with reduced amplitude. In the alkaline form of the mutant E46A the formation of the I(2)-like intermediate is even faster as is the proton uptake (tau = 20 micros at pH 8.3). No dye binding occurred in E46A, suggesting the absence of a conformational change. In all of the systems proton release is synchronized with the decay of I(2). Our results support mechanisms in which the chromophore of PYP is protonated directly from the external medium rather than by the internal donor E46.

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Section: Discussionsupporting

confidence: 77%

Section: Discussionsupporting

confidence: 65%

Kinetics of Proton Uptake and Dye Binding by Photoactive Yellow Protein in Wild Type and in the E46Q and E46A Mutants

et al. 2002

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“…In an earlier study, presence of one isosbestic point at 600 nm has also been shown for BCP-BSA interaction. [31] Also, appear of isosbestic point in electronic absorption spectra of interaction between bromo phenol blue with bovine serum albumin and -globulin in acidic solution , this indicated on present equilibrium between free and bound (BPB) dye. [32] Interaction of surfactant with anionic azo dyes (Methyl Orange and Methyl Red)by absorption spectroscopy in neutral medium and at different pH.…”

Section: Introduction Definitions and Properties Of Isosbestic Pointmentioning

confidence: 94%

Importance of isosbestic point in spectroscopy: a review

Hemdan¹,

Jebaly²,

Ali³

2024

Journal of Science and Humanities

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General trends in the development of investigations of isosbestic point, involving the chemical reaction in aqueous solutions are considered. The electronic absorption spectra, fluoresce spectral, equilibrium, and terminological aspects, as well as the possible schemes of formation of two compounds at the same wavelength, are discussed. The contributions of different methods to estimate the concentration of a substance by isosbestic point are analyzed. The interrelationship between the characteristics isosbestic point and phase rule is discussed.

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Heteroassociation of the bromine-containing anions of sulfophthaleins in aqueous solution

Shapovalov

Kiseleva

2010

Russ Chem Bull

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The ability of bromine containing anions of sulfophthalein dyes, such as bromophenol blue (BPB), bromocresol green (BCG), bromocresol purple (BCP), bromothymol blue (BTB), as well as non substituted phenol red (PhR), to form heteroassociates in aqueous solution was investigated. Singly and doubly charged anions BPB, BCG, BCP, BTB, and PhR (HAn -, An 2-) are capable of forming stable heteroassociates of composition Ct + •HAn -and (Ct + ) 2 •An 2-with cationic polymethine dyes (Ct + ), such as pinacyanol and quinaldine red. The enthalpies of formation of the dye ions and heteroassociates were calculated by semiempirical methods, and the most probable structure of heteroassociates was determined.Sulfophthalein dyes have long been effectively used as acid base and metallochromic indicators, and also as analytical reagents for photometric determination of many metal ions, surfactants, organic bases, etc. 1-4 The sulfo phthaleins possess a range of specific features, such as the possibility of the separate existence of anionic protolytic forms, their stability, weak dimerization, good resolution of absorption bands of singly and doubly charged ions in the electronic spectra and, as a result, the high color con trast of indicator transitions. 1,4-7 In this class of com pounds, bromo derivatives of sulfophthaneins (BDSP), such as bromophenol blue (BPB), bromocresol green (BCG), bromocresol purple (BCP), and bromothymol blue (BTB), have attracted attention. These BDSP are also used for the high precision in situ determination of pH of pure 8,9 and natural waters (a mixture of sulfophthaleins is used). 10,11 BDSP is the basis of sensitive elements of optical рН sensors, 12 fiber optic biosensors, and chips 13-16 (e.g., BTB and acetylcholine esterase doped with a sol gel film are sensitive to the content of organophosphate pesticide). 14 Indicators are effectively used for the study of serum albumin. 17-20 One of the most promising fields of application of BDSP as analytical reagents is the quanti tative determination of the range of components in bio agents and pharmaceuticals: antiviral (indinavir), 21 anti microbial (enoxacin), 22 antibacterial (gatifloxacin, 23 sparfloxacin, 24 ofloxacin 25 ), antihistaminic (oxomem azine), 26,27 and hypotensive (irbesartan, 28 nifedipine, 29 dilti azem 30 ) agents, antidepressants (tianeptine, 31 trazodone, 32 sertraline, fluoxetine, venlafaxine 33 ), antiulcer agents (raniti dine), 34 etc. 35,36 It is noteworthy that the high precision and rapid methods described above are based on the for mation of heteroassociates (ionic pairs) between the com ponent to be determined and the anionic forms of BDSP. Very often heteroassociates are extracted into an organic phase (tricloromethane, 21,22,25,27,29,30,32 dichlorometh ane 26,36 ). Let us note that solutions of BDSP are rather complex, since each of the dyes is subjected to many pro tolytic and tautomeric transformations (even in a thin film state BDSP can exist as an equilibrium mixture of associated lactone, quinoid, and zwitterionic form...

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Multivariate analysis of the association of bromocresol purple anion with bovine serum albumin

Cited by 7 publications

References 25 publications

Kinetics of Proton Uptake and Dye Binding by Photoactive Yellow Protein in Wild Type and in the E46Q and E46A Mutants

Kinetics of Proton Uptake and Dye Binding by Photoactive Yellow Protein in Wild Type and in the E46Q and E46A Mutants

Importance of isosbestic point in spectroscopy: a review

Heteroassociation of the bromine-containing anions of sulfophthaleins in aqueous solution

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