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Heat-Induced gelation mechanism of blood plasma modulated by cysteine

his work aims to determine changes at molecular level of plasma proteins provoked by adding cysteine (Cys, 0.025% to 0.35% w/v) as a reducing agent and their relationship with the heat-induced gel properties obtained when subsequently the solutions were submitted to a thermal treatment. Results show that adding Cys to plasma solutions at concentrations ≥0.15% actually entails modifications in the secondary structure of their main proteins, that is, serum albumin-α-helix rich-and globulin fraction-β-sheet rich. Basically, a reduction of the intensity of the infrared (IR) bands assigned to both structures takes place concomitant to an increase of extended structures that seem to act as intermediates for the subsequent protein aggregation process through nonnative intermolecular β-sheets. Cleavage of disulfide bonds is also evidenced at Cys concentrations ≥0.15% by nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), with the effects being directly proportional to Cys concentration. However, beneficial effects on gel hardness are gradually obtained at Cys concentrations ≤0.15%, that is, when the effects at molecular level are at most just budding, while not more improvements on this textural parameter are obtained at higher Cys concentrations. By contrast, water retention capacity is gradually diminishing as Cys concentration increases, but with a significant reduction only obtained at the highest tested concentration. These results suggest a negative effect of Cys on gel microstructure at high concentrations, which probably can be attributed to protein aggregation taking place at room temperature

This work was financially supported by the Spanish Government MICIIN Project ref. AGL2007-60917 and the Univ. of Girona project ref. ASING2011. We would also like to thank S.A. Norfrisa (Girona, Spain) for the kind donation of blood samples and Mr. Mark King of the Kellogg Co. in Battle Creek, Mich., for proof reading

© Journal of Food Science, 2015, vol. 80, núm. 3, p. C515-C521

Wiley

Author: Saguer Hom, Elena
Álvarez, Patricia
Fort Fort, Nuri
Espigulé, Eva
Parés i Oliva, Dolors
Toldrà i Alegret, Mònica
Carretero Romay, Carmen
Date: 2015
Abstract: his work aims to determine changes at molecular level of plasma proteins provoked by adding cysteine (Cys, 0.025% to 0.35% w/v) as a reducing agent and their relationship with the heat-induced gel properties obtained when subsequently the solutions were submitted to a thermal treatment. Results show that adding Cys to plasma solutions at concentrations ≥0.15% actually entails modifications in the secondary structure of their main proteins, that is, serum albumin-α-helix rich-and globulin fraction-β-sheet rich. Basically, a reduction of the intensity of the infrared (IR) bands assigned to both structures takes place concomitant to an increase of extended structures that seem to act as intermediates for the subsequent protein aggregation process through nonnative intermolecular β-sheets. Cleavage of disulfide bonds is also evidenced at Cys concentrations ≥0.15% by nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), with the effects being directly proportional to Cys concentration. However, beneficial effects on gel hardness are gradually obtained at Cys concentrations ≤0.15%, that is, when the effects at molecular level are at most just budding, while not more improvements on this textural parameter are obtained at higher Cys concentrations. By contrast, water retention capacity is gradually diminishing as Cys concentration increases, but with a significant reduction only obtained at the highest tested concentration. These results suggest a negative effect of Cys on gel microstructure at high concentrations, which probably can be attributed to protein aggregation taking place at room temperature
This work was financially supported by the Spanish Government MICIIN Project ref. AGL2007-60917 and the Univ. of Girona project ref. ASING2011. We would also like to thank S.A. Norfrisa (Girona, Spain) for the kind donation of blood samples and Mr. Mark King of the Kellogg Co. in Battle Creek, Mich., for proof reading
Format: application/pdf
ISSN: 0022-1147 (versió paper)
1750-3841 (versió electrònica)
Document access: http://hdl.handle.net/10256/11586
Language: eng
Publisher: Wiley
Collection: MEC/PN 2007-2011/AGL2007-60917
Reproducció digital del document publicat a: http://dx.doi.org/10.1111/1750-3841.12805
Articles publicats (D-EQATA)
Is part of: © Journal of Food Science, 2015, vol. 80, núm. 3, p. C515-C521
Rights: Tots els drets reservats
Subject: Hematologia veterinària
Veterinary hematology
Porcs -- Indústria i comerç
Porcs - Industrie et commerce
Plasma sanguini
Blood plasma
Title: Heat-Induced gelation mechanism of blood plasma modulated by cysteine
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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