Production of angiotensin-I-converting enzyme inhibitory peptides from casein hydrolysis by Lactobacillus delbrueckii subsp. lactis CRL581

HEBERT, E.M.; MAMONE, G.; PICARIELLO, G.; MOZZI, F.; SAVOY DE GIORI, G.; FERRANTI, P.

Egmond aan Zee, Netherlands

Simposio; EIGTH SYMPOSIUM ON LACTIC ACID BACTERIA. GENETICS, METABOLISM AND APPLICATIONS.; 2005

Federation of European Microbiological Societies (FEMS)

Many biologically active peptides are encrypted in milk proteins and can be released by the proteolytic system of several lactic acid bacteria (LAB) during dairy processing. The proteolytic system of LAB consists of a cell envelope-associated proteinase, membrane-bound transport systems and several intracellular peptidases. In the present work, the ability of the Lactobacillus delbrueckii subsp. lactis CRL581 cell envelope-associated proteinase to release angiotensin-I-converting enzyme (ACE) inhibitory biopeptides from milk caseins was evaluated. The CRL581 proteinase (Prt581) mainly hydrolysed a- and ß-casein and k-casein to a much lesser extent. The peptides from a- and ß-caseins hydrolysates were purified by reversed-phase high-pressure liquid chromatography and their amino acid compositions analysed by mass spectrometry. Thus, the cleavage site specificity of Prt581 on a- and ß-casein could be determined. a- and ß-casein hydrolysates showed 53 and 40% ACE-inhibitory activities, respectively, measured by an in vitro ACE inhibition test. The highest ACE-inhibitory fraction derived from ß-casein contained a peptide mixture of ß-casein f194-206 (QEPVLGPVRGPFP) and f198-206 (LGPVRGPFP), both having features in common with the octapeptide angiotensin II, the main product of the ACE enzyme. The bioactivities of these peptides remain to be demonstrated in vivo.