Proteome analysis of Lactobacillus helveticus H9 during growth in skim milk.
J Dairy Sci
; 97(12): 7413-25, 2014 Dec.
Article
em En
| MEDLINE
| ID: mdl-25306273
ABSTRACT
Lactobacillus helveticus H9 was isolated from traditionally fermented yak milk in Tibet (China) with the ability to produce the antihypertensive peptides Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP) during milk fermentation. To understand the changes in the protein expression of L. helveticus H9, proteome analysis was performed at 3 different growth stages, lag phase (pH 6.1), log phase (pH 5.1), and stationary phase (pH 4.5) using 2-dimensional electrophoresis (2-DE). Further analysis showed that 257 differential protein spots were found and 214 protein spots were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). The cellular functions of the differentially expressed proteins were complex. Interestingly, the proteolytic system-related proteins aminopeptidase N (PepN), aminopeptidase E (PepE), endopeptidase O2 (PepO2), and oligopeptide transport system permease protein (OppC) were observed only on the maps of pH 5.1 and pH 4.5, which was consistent with the presence of angiotensin I-converting enzyme (ACE)-inhibitory peptides VPP and IPP during these 2 growth stages (log phase and stationary phase). These results, combined with a previous study of gene expression of the proteolytic system, led us to conclude that the Opp transport system, pepE, and pepO2 are likely related to the production of ACE-inhibitory peptides.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteoma
/
Proteômica
/
Leite
/
Lactobacillus helveticus
Limite:
Animals
País/Região como assunto:
Asia
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article