scholarly journals Role of Alkaline Serine Protease, Asp, in Vibrio alginolyticus Virulence and Regulation of Its Expression by LuxO-LuxR Regulatory System

2009 ◽  
Vol 19 (5) ◽  
pp. 431-438 ◽  
Author(s):  
Haopeng Rui
Keyword(s):  
Serine Protease ◽  
Regulatory System ◽  
Vibrio Alginolyticus ◽  
Alkaline Serine Protease

Correction: Structural modeling and role of HAX-1 as a positive allosteric modulator of human serine protease HtrA2

2020 ◽  
Vol 477 (2) ◽  
pp. 459-459
Author(s):  
Lalith K. Chaganti ◽  
Shubhankar Dutta ◽  
Raja Reddy Kuppili ◽  
Mriganka Mandal ◽  
Kakoli Bose
Keyword(s):  
Serine Protease ◽  
Structural Modeling ◽  
Allosteric Modulator ◽  
Positive Allosteric Modulator

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

scholarly journals Carbohydrate-controlled serine protease inhibitor (serpin) production in Bifidobacterium longum subsp. longum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Duboux ◽  
M. Golliard ◽  
J. A. Muller ◽  
G. Bergonzelli ◽  
C. J. Bolten ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Serine Protease ◽  
Serine Proteases ◽  
Intestinal Tract ◽  
Defense Mechanism ◽  
Inflammatory Diseases ◽  
Bifidobacterium Longum ◽  
Serine Protease Inhibitor ◽  
Innate Defense

AbstractThe Serine Protease Inhibitor (serpin) protein has been suggested to play a key role in the interaction of bifidobacteria with the host. By inhibiting intestinal serine proteases, it might allow bifidobacteria to reside in specific gut niches. In inflammatory diseases where serine proteases contribute to the innate defense mechanism of the host, serpin may dampen the damaging effects of inflammation. In view of the beneficial roles of this protein, it is important to understand how its production is regulated. Here we demonstrate that Bifidobacterium longum NCC 2705 serpin production is tightly regulated by carbohydrates. Galactose and fructose increase the production of this protein while glucose prevents it, suggesting the involvement of catabolite repression. We identified that di- and oligosaccharides containing galactose (GOS) and fructose (FOS) moieties, including the human milk oligosaccharide Lacto-N-tetraose (LNT), are able to activate serpin production. Moreover, we show that the carbohydrate mediated regulation is conserved within B. longum subsp. longum strains but not in other bifidobacterial taxons harboring the serpin coding gene, highlighting that the serpin regulation circuits are not only species- but also subspecies- specific. Our work demonstrates that environmental conditions can modulate expression of an important effector molecule of B. longum, having potential important implications for probiotic manufacturing and supporting the postulated role of serpin in the ability of bifidobacteria to colonize the intestinal tract.

Molecular Cloning, Nucleotide Sequence, and Expression of the Structural Gene for Alkaline Serine Protease from AlkaliphilicBacillussp. 221

1992 ◽  
Vol 56 (9) ◽  
pp. 1455-1460 ◽  
Author(s):  
Hideto Takami ◽  
Tetsuo Kobayashi ◽  
Masato Kobayashi ◽  
Mami Yamamoto ◽  
Satoshi Nakamura ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Molecular Cloning ◽  
Serine Protease ◽  
Structural Gene ◽  
Alkaline Serine Protease

Production, purification and characterization of thermomycolase, the extracellular serine protease of the thermophilic fungus Malbranchea pulchella var. sulfurea

1976 ◽  
Vol 22 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Poh Seng Ong ◽  
G. Maurice Gaucher
Keyword(s):  
Serine Protease ◽  
Thermophilic Fungus ◽  
Amino Acid Residues ◽  
Submerged Cultures ◽  
Ph Optimum ◽  
Alkaline Serine Protease ◽  
Associated Production ◽  
Specificity Study ◽  
Malbranchea Pulchella ◽  
The Stability

The thermophilic fungus Malbranchea pulchella produces a single extracellular, alkaline, serine protease when grown at 45 °C, on 2% casein as sole carbon source. The growth-associated production of protease in submerged cultures was inhibited by addition of glucose, amino acids, or yeast extract. A simple four-step purification which yields homogeneous protease in 78% yield is described. The protease has an isoelectric point of 6.0, a pH optimum of 8.5, and is completely inhibited by serine protease inhibitors. A specificity study with small synthetic ester substrates indicated that the protease preferentially hydrolyzed bonds situated on the carboxyl side of aromatic or apolar amino acid residues which are not β-branched, positively charged or of the D configuration. Peptidase substrates and others such as N-acetyl-L-tyrosine-ethyl ester were not hydrolyzed. The protease was stable over a broad range of pH (6.5–9.5 at 30 °C, 20 h), and was particularly thermostable (t1/2 = 110 min at 73 °C, pH 7.4) in the presence of Ca2+ (10 mM). Macromolecules and Ca2+ also provide protection against the significant autolysis which occurs at pure protease concentrations greater than 0.01 mg/ml, as well as against surface denaturation which is enhanced by the presence of a silicone antifoam agent. Hence the stability of protease in submerged cultures is rationalized.

scholarly journals Spontaneous Gac Mutants of Pseudomonas Biological Control Strains: Cheaters or Mutualists?

2011 ◽  
Vol 77 (20) ◽  
pp. 7227-7235 ◽  
Author(s):  
William W. Driscoll ◽  
John W. Pepper ◽  
Leland S. Pierson ◽  
Elizabeth A. Pierson
Keyword(s):  
Alternative Hypothesis ◽  
Natural Populations ◽  
Regulatory System ◽  
Wild Type ◽  
Content Type ◽  
The Public ◽  
Extracellular Metabolites ◽  
Mutualistic Interaction ◽  
Alternative Hypotheses

ABSTRACTBacteria rely on a range of extracellular metabolites to suppress competitors, gain access to resources, and exploit plant or animal hosts. The GacS/GacA two-component regulatory system positively controls the expression of many of these beneficial external products in pseudomonad bacteria. Natural populations often contain variants with defective Gac systems that do not produce most external products. These mutants benefit from a decreased metabolic load but do not appear to displace the wild type in nature. How could natural selection maintain the wild type in the presence of a mutant with enhanced growth? One hypothesis is that Gac mutants are “cheaters” that do not contribute to the public good, favored within groups but selected against between groups, as groups containing more mutants lose access to ecologically important external products. An alternative hypothesis is that Gac mutants have a mutualistic interaction with the wild type, so that each variant benefits by the presence of the other. In the biocontrol bacteriumPseudomonas chlororaphisstrain 30-84, Gac mutants do not produce phenazines, which suppress competitor growth and are critical for biofilm formation. Here, we test the predictions of these alternative hypotheses by quantifying interactions between the wild type and the phenazine- and biofilm-deficient Gac mutant within growing biofilms. We find evidence that the wild type and Gac mutants interact mutualistically in the biofilm context, whereas a phenazine-defective structural mutant does not. Our results suggest that the persistence of alternative Gac phenotypes may be due to the stabilizing role of local mutualistic interactions.

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