scholarly journals Mechanistic Dissection of the Enzyme Complexes Involved in Biosynthesis of Lacticin 3147 and Nisin

2008 ◽  
Vol 74 (21) ◽  
pp. 6591-6597 ◽  
Author(s):  
Anneke Kuipers ◽  
Jenny Meijer-Wierenga ◽  
Rick Rink ◽  
Leon D. Kluskens ◽  
Gert N. Moll
Keyword(s):  
Lactococcus Lactis ◽  
Bifunctional Enzyme ◽  
Bifunctional Enzymes ◽  
Lacticin 3147 ◽  
Two Component ◽  
Modified Peptides ◽  
Enzyme Complexes ◽  
Insight Into ◽  
Design And Production

ABSTRACT The thioether rings in the lantibiotics lacticin 3147 and nisin are posttranslationally introduced by dehydration of serines and threonines, followed by coupling of these dehydrated residues to cysteines. The prepeptides of the two-component lantibiotic lacticin 3147, LtnA1 and LtnA2, are dehydrated and cyclized by two corresponding bifunctional enzymes, LtnM1 and LtnM2, and are subsequently processed and exported via one bifunctional enzyme, LtnT. In the nisin synthetase complex, the enzymes NisB, NisC, NisT, and NisP dehydrate, cyclize, export, and process prenisin, respectively. Here, we demonstrate that the combination of LtnM2 and LtnT can modify, process, and transport peptides entirely different from LtnA2 and that LtnT can process and transport unmodified LtnA2 and unrelated peptides. Furthermore, we demonstrate a higher extent of NisB-mediated dehydration in the absence of thioether rings. Thioether rings apparently inhibited dehydration, which implies alternating actions of NisB and NisC. Furthermore, certain (but not all) NisC-cyclized peptides were exported with higher efficiency as a result of their conformation. Taken together, these data provide further insight into the applicability of Lactococcus lactis strains containing lantibiotic enzymes for the design and production of modified peptides.

Centrifugal Flow in a Rotor-Stator Cavity

2005 ◽  
Vol 127 (4) ◽  
pp. 787-794 ◽  
Author(s):  
Sébastien Poncet ◽  
Roland Schiestel ◽  
Marie-Pierre Chauve
Keyword(s):  
Laser Doppler Anemometer ◽  
Second Order ◽  
Control Parameters ◽  
Complex Flows ◽  
Order Model ◽  
Pressure Transducers ◽  
Numerical Predictions ◽  
Two Component ◽  
First Time ◽  
Insight Into

The present work considers the turbulent flow inside an annular rotor-stator cavity with and without centrifugal throughflow. Extensive measurements performed using a two-component laser-Doppler anemometer technique, and pressure transducers are compared to numerical predictions based on one-point statistical modeling using a low-Reynolds-number second-order full-stress transport closure. A study of the flow control parameters is performed, and, for the first time, a better insight into the transition from Batchelor to Stewartson types of flow is gained from this study. The advanced second-order model is confirmed to be the adequate level of closure to describe such complex flows.

scholarly journals Regulation of immunity to the two-component lantibiotic, lacticin 3147, by the transcriptional repressor LtnR

2001 ◽  
Vol 39 (4) ◽  
pp. 982-993 ◽  
Author(s):  
Olivia McAuliffe ◽  
Triona O'Keeffe ◽  
Colin Hill ◽  
R. Paul Ross
Keyword(s):  
Transcriptional Repressor ◽  
Lacticin 3147 ◽  
Two Component

Enzymic oxidation of monoclonal antibodies by soluble and immobilized bifunctional enzyme complexes

1990 ◽  
Vol 510 ◽  
pp. 321-329 ◽  
Author(s):  
Beka Solomon ◽  
Rela Koppel ◽  
Fidi Schwartz ◽  
Gideon Fleminger
Keyword(s):  
Monoclonal Antibodies ◽  
Bifunctional Enzyme ◽  
Enzymic Oxidation ◽  
Enzyme Complexes

The SagS sensory protein modulates biofilm formation and c-di-GMP levels by Pseudomonas aeruginosa in response to glucose-6-phosphate.

2020 ◽  
Author(s):  
Soyoung Park ◽  
Jozef Dingemans ◽  
Madison Gowett ◽  
Karin Sauer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Genetic Analysis ◽  
Signaling Pathway ◽  
Biofilm Formation ◽  
Phosphate Concentration ◽  
Dependent Manner ◽  
Diguanylate Cyclase ◽  
Swarming Motility ◽  
Two Component ◽  
Insight Into

<p>In <em>Pseudomonas aeruginosa</em>, the orphan two-component sensor SagS contributes to both, the transition to biofilm formation and to biofilm cells gaining their heightened tolerance to antimicrobials. However, little is known about the identity of the signals or conditions sensed by SagS to induce the switch to the sessile, drug tolerant mode of growth. Using a modified Biolog phenotype assay to screen for compounds that modulate attachment in a SagS-dependent manner, we identified glucose-6-phosphate to enhance attachment in a manner dependent on the glucose-6-phosphate concentration and SagS. The stimulatory effect was not limited to the attachment as glucose-6-phosphate likewise enhanced biofilm formation. We show that exposure to glucose-6-phosphate results in decreased swarming motility but increased cellular c-di-GMP levels in biofilms. Genetic analysis indicated that the diguanylate cyclase NicD is an activator of biofilm formation and is not only required for enhanced biofilm formation in response to glucose-6-phosphate but also interacts with SagS. Our findings indicate glucose-6-phosphate to likely mimic a signal or conditions sensed by SagS to activate its motile-sessile switch function. Additionally, our findings provide new insight into the interfaces between the ligand-mediated TCS signaling pathway and c-di-GMP levels.</p>

scholarly journals Microplate Bioassay for Nisin in Foods, Based on Nisin-Induced Green Fluorescent Protein Fluorescence

2003 ◽  
Vol 69 (7) ◽  
pp. 4214-4218 ◽  
Author(s):  
J. Reunanen ◽  
P. E. J. Saris
Keyword(s):  
Green Fluorescent Protein ◽  
Lactococcus Lactis ◽  
Culture Supernatant ◽  
Fluorescent Protein ◽  
Green Fluorescent Protein Fluorescence ◽  
Regulatory Proteins ◽  
Protein Fluorescence ◽  
Gene Encoding ◽  
Two Component ◽  
Green Fluorescent

ABSTRACT A plasmid coding for the nisin two-component regulatory proteins, NisK and NisR, was constructed; in this plasmid a gfp gene (encoding the green fluorescent protein) was placed under control of the nisin-inducible nisF promoter. The plasmid was transformed into non-nisin-producing Lactococcus lactis strain MG1614. The new strain could sense extracellular nisin and transduce it to green fluorescent protein fluorescence. The amount of fluorescence was dependent on the nisin concentration, and it could be measured easily. By using this strain, an assay for quantification of nisin was developed. With this method it was possible to measure as little as 2.5 ng of pure nisin per ml in culture supernatant, 45 ng of nisin per ml in milk, 0.9 μg of nisin in cheese, and 1 μg of nisin per ml in salad dressings.

scholarly journals The Role of Proteins in Biosilicification

Scientifica ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Daniel Otzen
Keyword(s):  
Self Assembly ◽  
Organic Matrix ◽  
Specific Protein ◽  
Colloidal Systems ◽  
Protein Properties ◽  
Modified Peptides ◽  
Fundamental Biology ◽  
Living Organisms ◽  
Insight Into

Although the use of silicon dioxide (silica) as a constituent of living organisms is mainly restricted to diatoms and sponges, the ways in which this process is controlled by nature continue to inspire and fascinate. Both diatoms and sponges carry out biosilificiation using an organic matrix but they adopt very different strategies. Diatoms use small and heavily modified peptides called silaffins, where the most characteristic feature is a modulation of charge by attaching long chain polyamines (LCPAs) to lysine groups. Free LCPAs can also cooperate with silaffins. Sponges use the enzyme silicatein which is homologous to the cysteine protease cathepsin. Both classes of proteins form higher-order structures which act both as structural templates and mechanistic catalysts for the polycondensation reaction. In both cases, additional proteins are continuously being discovered which modulate the process further. This paper concentrates on the role of these proteins in the biosilification process as well as in various applications, highlighting areas where focus on specific protein properties may provide further insight. The field of biosilification is a crossroads of different disciplines, where insight into the energetics and mechanisms of molecular self-assembly combine with fundamental biology, complex multicomponent colloidal systems, and an impressive array of potential technological applications.

scholarly journals Enhancement of 2-methylbutanal formation in cheese by using a fluorescently tagged Lacticin 3147 producing Lactococcus lactis strain

2004 ◽  
Vol 93 (3) ◽  
pp. 335-347 ◽  
Author(s):  
Pilar Fernández de Palencia ◽  
Marta de la Plaza ◽  
M.Luz Mohedano ◽  
M.Carmen Martı́nez-Cuesta ◽  
Teresa Requena ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Lacticin 3147 ◽  
Lactis Strain

scholarly journals Nisin-Controlled Production of Pediocin PA-1 and Colicin V in Nisin- and Non-Nisin-Producing Lactococcus lactis Strains

2004 ◽  
Vol 70 (8) ◽  
pp. 5030-5032 ◽  
Author(s):  
Nikki Horn ◽  
Antonio Fernández ◽  
Helen M. Dodd ◽  
Michael J. Gasson ◽  
Juan M. Rodríguez
Keyword(s):  
Lactococcus Lactis ◽  
Chimeric Genes ◽  
Two Component ◽  
Genes Encoding ◽  
Colicin V ◽  
Nisin Producer

ABSTRACT The introduction of chimeric genes encoding the fusion leader of lactococcin A-propediocin PA-1 or procolicin V under the control of the inducible nisA promoter and the lactococcin A-dedicated secretion genes (lcnCD) into Lactococcus lactis strains, including a nisin producer, expressing the two component regulator NisRK led to the production or pediocin PA-1 or colicin V, respectively.

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