Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation.
BACKGROUND
In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation.


RESULTS
In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p). Bidimensional electrophoresis and carbonylated protein identification from TRX-deficient and TRX-overexpressing cells revealed that glycolysis and fermentation-related proteins are specific targets of Trx2p protection. Indeed, the TRX2 overexpressing strain presented increased activity of the central carbon metabolism enzymes. Interestingly, Trx2p specifically preserved alcohol dehydrogenase I (Adh1p) from carbonylation, decreased oligomer aggregates and increased its enzymatic activity.


CONCLUSIONS
The identified proteins suggest that the fermentative capacity detriment observed under industrial conditions in T73 wine commercial strain results from the oxidative carbonylation of specific glycolytic and fermentation enzymes. Indeed, increased thioredoxin levels enhance the performance of key fermentation enzymes such as Adh1p, which consequently increases fermentative capacity.
Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, CSIC, Apartado de Correos, 73. Burjassot (Valencia). E-46100, Spain.
Rocío
R
Gómez-Pastor
Roberto
R
Pérez-Torrado
Elisa
E
Cabiscol
Joaquim
J
Ros
Emilia
E
Matallana
D000426:Alcohol Dehydrogenase / Q000378:metabolism; D018533:Biomass; D005285:Fermentation; D006019:Glycolysis; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D050050:Protein Carbonylation; D015202:Protein Engineering; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013879:Thioredoxins / Q000235:genetics* / Q000378:metabolism
D029701:Saccharomyces cerevisiae Proteins; C516110:TRX2 protein, S cerevisiae; D013879:Thioredoxins; D000426:Alcohol Dehydrogenase