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Unaided efficient transglutaminase cross-linking of whey proteins strongly impacts the formation and structure of protein alginate particles

Madsen, Mikkel ; Khan, Sanaullah ; Kunstmann, Sonja ; Aachmann, Finn L. ; Ipsen, Richard ; Westh, Peter ; Emanuelsson, Cecilia LU orcid and Svensson, Birte (2022) In Food Chemistry: Molecular Sciences 5.
Abstract

There is a dogma within whey protein modification, which dictates the necessity of pretreatment to enzymatic cross-linking of β-lactoglobulin (β-Lg). Here microbial transglutaminase (MTG) cross-linked whey proteins and β-Lg effectively in 50 mM NaHCO3, pH 8.5, without pretreatment. Cross-linked β-Lg spanned 18 to >240 kDa, where 6 of 9 glutamines reacted with 8 of 15 lysines. The initial isopeptide bond formation caused loss of β-Lg native structure with t1/2 = 3 h, while the polymerization occurred with t1/2 = 10 h. Further, cross-linking effects on protein carbohydrate interaction have been overlooked, leaving a gap in understanding of these complex food matrices. Complexation with alginate showed... (More)

There is a dogma within whey protein modification, which dictates the necessity of pretreatment to enzymatic cross-linking of β-lactoglobulin (β-Lg). Here microbial transglutaminase (MTG) cross-linked whey proteins and β-Lg effectively in 50 mM NaHCO3, pH 8.5, without pretreatment. Cross-linked β-Lg spanned 18 to >240 kDa, where 6 of 9 glutamines reacted with 8 of 15 lysines. The initial isopeptide bond formation caused loss of β-Lg native structure with t1/2 = 3 h, while the polymerization occurred with t1/2 = 10 h. Further, cross-linking effects on protein carbohydrate interaction have been overlooked, leaving a gap in understanding of these complex food matrices. Complexation with alginate showed that β-Lg cross-linking decreased onset of particle formation, hydrodynamic diameter, stoichiometry (β-Lg/alginate) and dissociation constant. The complexation was favored at higher temperatures (40 °C), suggesting that hydrophobic interactions were important. Thus, β-Lg was cross-linked without pretreatment and the resulting polymers gave rise to altered complexation with alginate.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Dynamic light scattering, Far- and near-UV CD, Intrinsic and ANS fluorescence spectra, LC-MS/MS cross-link identification, Molecular dynamics inter-residue distance analysis, Size exclusion chromatography
in
Food Chemistry: Molecular Sciences
volume
5
article number
100137
publisher
Elsevier
external identifiers
  • scopus:85138554980
  • pmid:36164490
ISSN
2666-5662
DOI
10.1016/j.fochms.2022.100137
language
English
LU publication?
yes
id
74b1b88a-792a-4746-9a88-d9df11dce449
date added to LUP
2022-12-05 16:29:03
date last changed
2025-10-19 04:34:41
@article{74b1b88a-792a-4746-9a88-d9df11dce449,
  abstract     = {{<p>There is a dogma within whey protein modification, which dictates the necessity of pretreatment to enzymatic cross-linking of β-lactoglobulin (β-Lg). Here microbial transglutaminase (MTG) cross-linked whey proteins and β-Lg effectively in 50 mM NaHCO<sub>3</sub>, pH 8.5, without pretreatment. Cross-linked β-Lg spanned 18 to &gt;240 kDa, where 6 of 9 glutamines reacted with 8 of 15 lysines. The initial isopeptide bond formation caused loss of β-Lg native structure with t<sub>1/2</sub> = 3 h, while the polymerization occurred with t<sub>1/2</sub> = 10 h. Further, cross-linking effects on protein carbohydrate interaction have been overlooked, leaving a gap in understanding of these complex food matrices. Complexation with alginate showed that β-Lg cross-linking decreased onset of particle formation, hydrodynamic diameter, stoichiometry (β-Lg/alginate) and dissociation constant. The complexation was favored at higher temperatures (40 °C), suggesting that hydrophobic interactions were important. Thus, β-Lg was cross-linked without pretreatment and the resulting polymers gave rise to altered complexation with alginate.</p>}},
  author       = {{Madsen, Mikkel and Khan, Sanaullah and Kunstmann, Sonja and Aachmann, Finn L. and Ipsen, Richard and Westh, Peter and Emanuelsson, Cecilia and Svensson, Birte}},
  issn         = {{2666-5662}},
  keywords     = {{Dynamic light scattering; Far- and near-UV CD; Intrinsic and ANS fluorescence spectra; LC-MS/MS cross-link identification; Molecular dynamics inter-residue distance analysis; Size exclusion chromatography}},
  language     = {{eng}},
  month        = {{12}},
  publisher    = {{Elsevier}},
  series       = {{Food Chemistry: Molecular Sciences}},
  title        = {{Unaided efficient transglutaminase cross-linking of whey proteins strongly impacts the formation and structure of protein alginate particles}},
  url          = {{http://dx.doi.org/10.1016/j.fochms.2022.100137}},
  doi          = {{10.1016/j.fochms.2022.100137}},
  volume       = {{5}},
  year         = {{2022}},
}