Differences in short peptide-substrate cleavage by two cell-envelope-located serine proteinases of Lactococcus lactis subsp. cremoris are related to secondary binding specificity

1990 ◽  
Vol 33 (4) ◽  
Author(s):  
FredA. Exterkate
Keyword(s):  
Lactococcus Lactis ◽  
Cell Envelope ◽  
Binding Specificity ◽  
Serine Proteinases ◽  
Peptide Substrate ◽  
Short Peptide ◽  
Lactococcus Lactis Subsp ◽  
Substrate Cleavage

Action of a cell-envelope proteinase (CEPIII-type) from Lactococcus lactis subsp. cremoris AM1 on bovine κ-casein

1994 ◽  
Vol 41 (6) ◽  
pp. 644-651 ◽  
Author(s):  
S. Visser ◽  
C. J. Slangen ◽  
A. J. P. M. Robben ◽  
W. D. van Dongen ◽  
W. Heerma ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Cell Envelope ◽  
Lactococcus Lactis Subsp ◽  
A Cell

Action of a cell-envelope proteinase (CEPIII-type) from Lactococcus lactis subsp. cremoris AM1 bovine ?-casein

1994 ◽  
Vol 41 (6) ◽  
pp. 644-651 ◽  
Author(s):  
S. Visser ◽  
C. J. Slangen ◽  
A. J. P. M. Robben ◽  
W. D. van Dongen ◽  
W. Heerma ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Cell Envelope ◽  
Lactococcus Lactis Subsp ◽  
A Cell

scholarly journals Specificity of two genetically related cell-envelope proteinases of Lactococcus lactis subsp. cremoris towards αs1-casein-(1–23)-fragment

1991 ◽  
Vol 273 (1) ◽  
pp. 135-139 ◽  
Author(s):  
F A Exterkate ◽  
A C Alting ◽  
C J Slangen
Keyword(s):  
Lactococcus Lactis ◽  
Hydrophobic Interaction ◽  
Cell Envelope ◽  
Sequence Similarity ◽  
Cleavage Sites ◽  
Hydrogen Bond Formation ◽  
Lactococcus Lactis Subsp ◽  
Related Cell ◽  
Close Sequence ◽  
Low Ionic Strength

The specificity of two genetically related cell-envelope serine proteinases (PI-type and PIII-type) of Lactococcus lactis subsp. cremoris towards the alpha s1-casein-(1-23)-fragment, an important intermediate product of primary chymosin-directed proteolysis in cheese, has been established. Both enzymes showed, at pH 6.5 and under relatively low-ionic-strength conditions, a characteristic, mutually different, cleavage pattern that seems, in the first instance, to be determined by the charge N-terminal to the cleaved bond. With Pi, three cleavage sites were found in the N-terminal positively charged part of the peptide and, with PIII, three sites were found in the C-terminal negatively charged part. Comparison of the specific cleavage sites in this peptide and those in β-casein revealed similarities with respect to the different residues which can occur N-terminally to the cleaved bond. The properties of these substrate residues match with the structural and various interactive features of the respective binding regions of the enzymes predicted on the basis of a close sequence similarity of the lactococcal proteinases with the subtilisin family. A hydrophobic interaction and/or hydrogen-bridge formation seems to govern the binding of the first amino acid residue N-terminal to the scissile bond. The more distantly N-terminally positioned sequence of residues apparently is attracted electrostatically by a negative charge in the binding region of PI and by a positive charge in that of PIII, provided that the opposite charge is is present at the appropriate position in this sequence. Hence a specific electrostatic binding may occur; additionally, hydrophobic interaction and/or hydrogen-bond formation is important.

Growth, nisA Gene Expression, and In Situ Activity of Novel Lactococcus lactis subsp. cremoris Costarter Culture in Commercial Hard Cheese Production

2017 ◽  
Vol 80 (12) ◽  
pp. 2137-2146 ◽  
Author(s):  
Dimitrios Noutsopoulos ◽  
Athanasia Kakouri ◽  
Eleftheria Kartezini ◽  
Dimitrios Pappas ◽  
Efstathios Hatziloukas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lactococcus Lactis ◽  
Starter Culture ◽  
Fold Increase ◽  
Raw Milk ◽  
Good Growth ◽  
Lactococcus Lactis Subsp ◽  
Quantitative Expression ◽  
Hard Cheese

ABSTRACT This study evaluated in situ expression of the nisA gene by an indigenous, nisin A–producing (NisA+) Lactococcus lactis subsp. cremoris raw milk genotype, represented by strain M78, in traditional Greek Graviera cheeses under real factory-scale manufacturing and ripening conditions. Cheeses were produced with added a mixed thermophilic and mesophilic commercial starter culture (CSC) or with the CSC plus strain M78 (CSC+M78). Cheeses were sampled after curd cooking (day 0), fermentation of the unsalted molds for 24 h (day 1), brining (day 7), and ripening of the brined molds (14 to 15 kg each) for 30 days in a fully controlled industrial room (16.5°C; 91% relative humidity; day 37). Total RNA was directly extracted from the cheese samples, and the expression of nisA gene was evaluated by real-time reverse transcription PCR (qRT-PCR). Agar overlay and well diffusion bioassays were correspondingly used for in situ detection of the M78 NisA+ colonies in the cheese agar plates and antilisterial activity in whole-cheese slurry samples, respectively. Agar overlay assays showed good growth (>8 log CFU/g of cheese) of the NisA+ strain M78 in coculture with the CSC and vice versa. The nisA expression was detected in CSC+M78 cheese samples only, with its expression levels being the highest (16-fold increase compared with those of the control gene) on day 1, followed by significant reduction on day 7 and almost negligible expression on day 37. Based on the results, certain intrinsic and mainly implicit hurdle factors appeared to reduce growth prevalence rates and decrease nisA gene expression, as well as the nisin A–mediated antilisterial activities of the NisA+ strain M78 postfermentation. To our knowledge, this is the first report on quantitative expression of the nisA gene in a Greek cooked hard cheese during commercial manufacturing and ripening conditions by using a novel, rarely isolated, indigenous NisA+ L. lactis subsp. cremoris genotype as costarter culture.

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