The effect of solution conditions on bovine serum albumin sulfhydryl reactivity

CP Chee, Richard Owusu-Apenten

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Solution conditions significantly affect sufhydryl (SH) group reactivity of bovine serum albumin (BSA). The objective of this study was to determine the effect of solution conditions on SH-reactivity. Conditions were varied in pH, temperature and the assortment of additives used. Changes in SH-group reactivity, defined in terms of a second order rate constant for SH- disulfide exchange (k, M-1s-1), were measured calorimetrically using 5,5’-dithiobis 2-nitrobenzoate (DTNB2-). All results were compared to BSA under standard conditions (pH 7.0, 50mM ionic strength, 250C). SH-reactivity increased from 0.49 M-1s-1 at pH 6, to 1.74 M-1s-1 at pH 7 and to 14.48 M-1s-1 at pH 8. This increase can be attributed to the pH microenvironment approaching the isoelectric point of cysteine. A 100C increase in temperature from 250C to 350C doubled the rate of SH-group reactivity from 1.74 M-1s-1 to 3.37 M-1s-1. When additives were used, sodium chloride (0.1M) and urea (8M) were found to increase SH-group reactivity from 1.74 M-1s-1 to 23.15 M-1s-1 and 12.03 M-1s-1 respectively; whilst addition of ethanol (10%) did not have any effect on SH-reactivity (k=1.77 M-1s-1). Increase of reactivity upon the addition of sodium chloride (1.0M) may be due to suppression of electrostatic repulsion between BSA and DTNB2-. The increase of SH-group reactivity upon addition of urea is due to the denaturation of BSA’s tertiary structure to expose the hidden SH-group. Findings from this study are important for better understanding of BSA structure and also characterization of SH-group location and reactivity.
LanguageEnglish
Title of host publicationUnknown Host Publication
Place of PublicationChicago, IL
Number of pages1
Publication statusPublished - 2003
Event2003 IFT Annual Meeting, July 12 - 16, Chicago, IL - Chicago, IL
Duration: 1 Jan 2003 → …

Conference

Conference2003 IFT Annual Meeting, July 12 - 16, Chicago, IL
Period1/01/03 → …

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Bovine Serum Albumin
Sodium Chloride
Urea
Denaturation
Ionic strength
Disulfides
Cysteine
Electrostatics
Rate constants
Ethanol
Temperature

Cite this

Chee, CP., & Owusu-Apenten, R. (2003). The effect of solution conditions on bovine serum albumin sulfhydryl reactivity. In Unknown Host Publication Chicago, IL.
Chee, CP ; Owusu-Apenten, Richard. / The effect of solution conditions on bovine serum albumin sulfhydryl reactivity. Unknown Host Publication. Chicago, IL, 2003.
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abstract = "Solution conditions significantly affect sufhydryl (SH) group reactivity of bovine serum albumin (BSA). The objective of this study was to determine the effect of solution conditions on SH-reactivity. Conditions were varied in pH, temperature and the assortment of additives used. Changes in SH-group reactivity, defined in terms of a second order rate constant for SH- disulfide exchange (k, M-1s-1), were measured calorimetrically using 5,5’-dithiobis 2-nitrobenzoate (DTNB2-). All results were compared to BSA under standard conditions (pH 7.0, 50mM ionic strength, 250C). SH-reactivity increased from 0.49 M-1s-1 at pH 6, to 1.74 M-1s-1 at pH 7 and to 14.48 M-1s-1 at pH 8. This increase can be attributed to the pH microenvironment approaching the isoelectric point of cysteine. A 100C increase in temperature from 250C to 350C doubled the rate of SH-group reactivity from 1.74 M-1s-1 to 3.37 M-1s-1. When additives were used, sodium chloride (0.1M) and urea (8M) were found to increase SH-group reactivity from 1.74 M-1s-1 to 23.15 M-1s-1 and 12.03 M-1s-1 respectively; whilst addition of ethanol (10{\%}) did not have any effect on SH-reactivity (k=1.77 M-1s-1). Increase of reactivity upon the addition of sodium chloride (1.0M) may be due to suppression of electrostatic repulsion between BSA and DTNB2-. The increase of SH-group reactivity upon addition of urea is due to the denaturation of BSA’s tertiary structure to expose the hidden SH-group. Findings from this study are important for better understanding of BSA structure and also characterization of SH-group location and reactivity.",
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Chee, CP & Owusu-Apenten, R 2003, The effect of solution conditions on bovine serum albumin sulfhydryl reactivity. in Unknown Host Publication. Chicago, IL, 2003 IFT Annual Meeting, July 12 - 16, Chicago, IL, 1/01/03.

The effect of solution conditions on bovine serum albumin sulfhydryl reactivity. / Chee, CP; Owusu-Apenten, Richard.

Unknown Host Publication. Chicago, IL, 2003.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

TY - GEN

T1 - The effect of solution conditions on bovine serum albumin sulfhydryl reactivity

AU - Chee, CP

AU - Owusu-Apenten, Richard

PY - 2003

Y1 - 2003

N2 - Solution conditions significantly affect sufhydryl (SH) group reactivity of bovine serum albumin (BSA). The objective of this study was to determine the effect of solution conditions on SH-reactivity. Conditions were varied in pH, temperature and the assortment of additives used. Changes in SH-group reactivity, defined in terms of a second order rate constant for SH- disulfide exchange (k, M-1s-1), were measured calorimetrically using 5,5’-dithiobis 2-nitrobenzoate (DTNB2-). All results were compared to BSA under standard conditions (pH 7.0, 50mM ionic strength, 250C). SH-reactivity increased from 0.49 M-1s-1 at pH 6, to 1.74 M-1s-1 at pH 7 and to 14.48 M-1s-1 at pH 8. This increase can be attributed to the pH microenvironment approaching the isoelectric point of cysteine. A 100C increase in temperature from 250C to 350C doubled the rate of SH-group reactivity from 1.74 M-1s-1 to 3.37 M-1s-1. When additives were used, sodium chloride (0.1M) and urea (8M) were found to increase SH-group reactivity from 1.74 M-1s-1 to 23.15 M-1s-1 and 12.03 M-1s-1 respectively; whilst addition of ethanol (10%) did not have any effect on SH-reactivity (k=1.77 M-1s-1). Increase of reactivity upon the addition of sodium chloride (1.0M) may be due to suppression of electrostatic repulsion between BSA and DTNB2-. The increase of SH-group reactivity upon addition of urea is due to the denaturation of BSA’s tertiary structure to expose the hidden SH-group. Findings from this study are important for better understanding of BSA structure and also characterization of SH-group location and reactivity.

AB - Solution conditions significantly affect sufhydryl (SH) group reactivity of bovine serum albumin (BSA). The objective of this study was to determine the effect of solution conditions on SH-reactivity. Conditions were varied in pH, temperature and the assortment of additives used. Changes in SH-group reactivity, defined in terms of a second order rate constant for SH- disulfide exchange (k, M-1s-1), were measured calorimetrically using 5,5’-dithiobis 2-nitrobenzoate (DTNB2-). All results were compared to BSA under standard conditions (pH 7.0, 50mM ionic strength, 250C). SH-reactivity increased from 0.49 M-1s-1 at pH 6, to 1.74 M-1s-1 at pH 7 and to 14.48 M-1s-1 at pH 8. This increase can be attributed to the pH microenvironment approaching the isoelectric point of cysteine. A 100C increase in temperature from 250C to 350C doubled the rate of SH-group reactivity from 1.74 M-1s-1 to 3.37 M-1s-1. When additives were used, sodium chloride (0.1M) and urea (8M) were found to increase SH-group reactivity from 1.74 M-1s-1 to 23.15 M-1s-1 and 12.03 M-1s-1 respectively; whilst addition of ethanol (10%) did not have any effect on SH-reactivity (k=1.77 M-1s-1). Increase of reactivity upon the addition of sodium chloride (1.0M) may be due to suppression of electrostatic repulsion between BSA and DTNB2-. The increase of SH-group reactivity upon addition of urea is due to the denaturation of BSA’s tertiary structure to expose the hidden SH-group. Findings from this study are important for better understanding of BSA structure and also characterization of SH-group location and reactivity.

M3 - Conference contribution

BT - Unknown Host Publication

CY - Chicago, IL

ER -

Chee CP, Owusu-Apenten R. The effect of solution conditions on bovine serum albumin sulfhydryl reactivity. In Unknown Host Publication. Chicago, IL. 2003