Partial Purification and Characterization of an Aminopeptidase from Lactobacillus helveticus CNRZ 32

Khalid, Noraini M.; Marth, Elmer H.

doi:10.1016/s0723-2020(11)80226-2

Cited by 63 publications

(77 citation statements)

References 20 publications

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“…PepX from L b . helveticas CNRZ32 was also inhibited by 0.1-2.5 mM Zn2+ (Khalid & Marth, 1990), in contrast to PepX from L b . helveticus LHE-511, which was slightly activated by 1 mM Zn2+ (Miyakawa e t al., 1994).…”

Section: Characterization Of the Purified Pepx Proteinmentioning

confidence: 89%

“…casei (Habibi-Najafi & Lee, 1994) and Lb. helveticzls (Khalid & Marth, 1990;Miyakawa e t al., 1994). However, pepX genes have only been cloned and sequenced from Lc.…”

Section: E V E S a N T O A N D O T H E R Smentioning

confidence: 99%

“…lactis and L b . helveticus (Meyer & Jordi, 1987;Miyakawa e t al., 1991Miyakawa e t al., , 1994Khalid & Marth, 1990;Miyakawa et al, 1994) and suggests the involvement of a sulfhydryl group in catalysis. Alternatively, the inhibition might be due to the steric hindrance by the thiol modifying agent rather than the direct role of cysteine in catalysis.…”

Section: Characterization Of the Purified Pepx Proteinmentioning

confidence: 99%

“…In contrast to our results, monomer forms have been described for Lb. helveticzls CNRZ32 and LHE-511, where the molecular mass of CNRZ32 PepX was estimated only by native PAGE (Khalid & Marth, 1990;Miyakawa e t al., 1994). Moreover, a monomer form has been described for Lb.…”

Section: E V E S a N T O A N D O T H E R S Mannmentioning

confidence: 99%

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An X-prolyl dipeptidyl aminopeptidase (pepX) gene from Lactobacillus helveticus

Vesanto¹,

Savijoki²,

Rantanen³

et al. 1995

Microbiology

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The X-prolyl dipeptidyl aminopeptidase gene (pepx) of an industrially used Lactobacillus helveticus strain has been detected by nucleic acid hybridization, cloned, characterized and sequenced. One ORF of 2379 bp with coding capacity for a 906 kDa protein (PepX) was found. The ORF was preceded by a typical prokaryotic promoter region. An inverted repeat structure with AG of -84.1 kJ mol-1 was found downstream of the coding region. The deduced amino acid sequence of the 906 kDa protein showed 49*3,494 and 777% homology with the PepX proteins from Lactococcus lactis subsp. lactis, Lc. lactis subsp. cremoris and Ladobacillus delbnreckii subsp. Iactis, respectively. Northern blotting revealed a 2.6 kb transcript and one transcription start site was identified via primer extension analysis using an A.L.F. sequencer. In a bioreactor study, the expression of pepX in Lb. helveticus was studied as a function of growth. Transcription of pepX was typical of exponential growth phase expression. The pepX gene has been cloned into pKK223-3 and expressed at a high level in Escherichia coli JM105. PepX was purified to homogeneity by ion-exchange and hydrophobic interaction chromatography. Optimum PepX activity was observed at pH 6 5 and 45 OC. According to gel filtration analysis, PepX is a dimer of 165 kDa. The enzyme was inactivated by heavy metal ions such as Cu2+, Cd2+ and Zn2+. EDTA and l,l0-phenanthroline did not decrease PepX activity significantly. It was completely inhibited by p-hydroxymercuribenzoate and reactivated by adding Dll, and strongly inhibited by PMSF. PepX is thus a metal-independent serine peptidase having functional sulfhydryl groups at or near the active site.

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Section: Characterization Of the Purified Pepx Proteinmentioning

confidence: 89%

“…casei (Habibi-Najafi & Lee, 1994) and Lb. helveticzls (Khalid & Marth, 1990;Miyakawa e t al., 1994). However, pepX genes have only been cloned and sequenced from Lc.…”

Section: E V E S a N T O A N D O T H E R Smentioning

confidence: 99%

Section: Characterization Of the Purified Pepx Proteinmentioning

confidence: 99%

Section: E V E S a N T O A N D O T H E R S Mannmentioning

confidence: 99%

See 2 more Smart Citations

An X-prolyl dipeptidyl aminopeptidase (pepX) gene from Lactobacillus helveticus

Vesanto¹,

Savijoki²,

Rantanen³

et al. 1995

Microbiology

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“…It is therefore suggested to consider the enzyme a X-propyl dipeptidyl peptidase. Dipeptidyl aminopeptidase activity was detected in several genera of lactic acid bacteria [7,10,23,24,28,34,39,55,64].…”

Section: Dipeptidyl Aminopeptidase Activitymentioning

confidence: 99%

Proteolytic, lipolytic and autolytic activities of enterococci strains isolated from Egyptian dairy products

El-Din¹,

El‐Soda

Ezzat

2002

Lait

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-Enterococci were isolated from Egyptian Domiatti and Mish cheeses made from raw milk. The proteolytic, lipolytic and autolytic activities of the isolated strains were studied to select the most appropriate cultures to be used for the enhancement of the organoleptic properties of cheese. The intracellular peptide hydrolase activities of enterococci strains were determined using various synthetic aminopeptidase and dipeptidyl-aminopeptidase substrates. 4-nitrophenyl and 2-nitrophenyl derivatives of fatty acids were used to measure the esterolytic activity of the different strains while emulsions of various triglycerides and butter fat were used to evaluate their lipolytic activities.The autolytic properties of the cultures were also considered. Three strains of Enterococcus faecium were freeze-shocked and evaluated as adjunct cultures in a cheese slurry system. All the strains exhibited an aminopeptidase activity hydrolysing leucyl 4-nitroanilide faster than the arginyl, alanyl, prolyl or glycyl derivatives. An active dipeptidyl-aminopeptidase activity was also detected. The Enterococcus faecium strains showed an active esterase system. The 4-nitrophenyl derivatives of the fatty acids were hydrolysed faster than the 2-nitrophenyl. The lipase substrates were hydrolysed according to the following order: tributyrin > tricaproin > tricaprylin > butterfat. The autolytic properties varied according to the strains tested. Cheese slurries ripened with adjunct Enterococcus faecium exhibited considerably higher levels of water-soluble nitrogen (WSN) and total free amino acids (FAA) when compared to the control after incubation for 5 d at 32 o C. With this finding, a high variability of some technologically relevant properties was found and could be the basis for the selection of specific cultures to be used as adjunct cultures in the production of traditional cheeses. Enterococcus / aminopeptidase / esterase / autolyse / levain atténué

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