Biology Reference
In-Depth Information
Chapter 52
Precipitation of Champagne Base Wine Proteins
Prior to 2D Electrophoresis
Clara Cilindre
Abstract
Numerous methods have been employed to depict the protein content of wines. Among them,
two-dimensional electrophoresis (2D-E) presents a powerful resolution, but has been poorly applied to
wine. Furthermore, 2D-E was coupled with various extraction methods of proteins without any reference
method for wine. Here, we describe a rapid method to extract proteins from a champagne base wine
through ultrafi ltration followed by precipitation with ethanol and trichloroacetic acid. More than 50 spots
were visualized on 2D-gels (7 cm, pH 3-6) by colloidal Coomassie Brilliant Blue staining.
Key words
Wine proteomics, Champagne, Grape, Chardonnay, Ultrafi ltration, Precipitation,
2D-electrophoresis
1
Introduction
Proteins are not the major components of wine, although they are
essential compounds, contributing to many organoleptic charac-
teristics. Indeed, wine proteins are implied in the foaming proper-
ties of sparkling wines [
1
,
2
], the interaction with wine volatile
compounds [
3
], the stabilization of tartaric salts [
4
], the decrease
in wine astringency [
5
] and, unfortunately, the formation of haze
in white wines [
6
,
7
]. Various factors are likely to modify the pro-
tein content of a wine, as for example, the grape variety [
8
], the
infection of grape berries by a widespread phytopathogen
Botrytis
cinerea
[
9
,
10
], the yeast strain employed for alcoholic fermenta-
tion [
11
], the aging on lees [
12
], and also various fi ning treat-
ments [
1
,
13
-
16
].
Since the end of the 90s, a broad range of methods for the
separation of specifi c or total proteins have been developed and
applied to wine [
17
], including chromatographic techniques [
6
,
13
,
16
,
18
-
20
], capillary gel electrophoresis [
18
,
21
], combinato-
rial peptide ligand libraries [
22
] or one-dimensional polyacryl-
amide gel electrophoresis [
1
,
6
,
14
,
15
,
23
,
24
]. 2D-E has been
