scholarly journals Cloning and Characterization of the Tetrocarcin A Gene Cluster from Micromonospora chalcea NRRL 11289 Reveals a Highly Conserved Strategy for Tetronate Biosynthesis in Spirotetronate Antibiotics

2008 ◽  
Vol 190 (17) ◽  
pp. 6014-6025 ◽  
Author(s):  
Jie Fang ◽  
Yiping Zhang ◽  
Lijuan Huang ◽  
Xinying Jia ◽  
Qi Zhang ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Structural Diversity ◽  
Biosynthetic Gene Cluster ◽  
Combinatorial Biosynthesis ◽  
In Vitro Characterization ◽  
Fused Gene ◽  
Micromonospora Chalcea

ABSTRACT Tetrocarcin A (TCA), produced by Micromonospora chalcea NRRL 11289, is a spirotetronate antibiotic with potent antitumor activity and versatile modes of action. In this study, the biosynthetic gene cluster of TCA was cloned and localized to a 108-kb contiguous DNA region. In silico sequence analysis revealed 36 putative genes that constitute this cluster (including 11 for unusual sugar biosynthesis, 13 for aglycone formation, and 4 for glycosylations) and allowed us to propose the biosynthetic pathway of TCA. The formation of d-tetronitrose, l-amicetose, and l-digitoxose may begin with d-glucose-1-phosphate, share early enzymatic steps, and branch into different pathways by competitive actions of specific enzymes. Tetronolide biosynthesis involves the incorporation of a 3-C unit with a polyketide intermediate to form the characteristic spirotetronate moiety and trans-decalin system. Further substitution of tetronolide with five deoxysugars (one being a deoxynitrosugar) was likely due to the activities of four glycosyltransferases. In vitro characterization of the first enzymatic step by utilization of 1,3-biphosphoglycerate as the substrate and in vivo cross-complementation of the bifunctional fused gene tcaD3 (with the functions of chlD3 and chlD4) to ΔchlD3 and ΔchlD4 in chlorothricin biosynthesis supported the highly conserved tetronate biosynthetic strategy in the spirotetronate family. Deletion of a large DNA fragment encoding polyketide synthases resulted in a non-TCA-producing strain, providing a clear background for the identification of novel analogs. These findings provide insights into spirotetronate biosynthesis and demonstrate that combinatorial-biosynthesis methods can be applied to the TCA biosynthetic machinery to generate structural diversity.

scholarly journals Characterization of the Saframycin A Gene Cluster from Streptomyces lavendulae NRRL 11002 Revealing a Nonribosomal Peptide Synthetase System for Assembling the Unusual Tetrapeptidyl Skeleton in an Iterative Manner

2007 ◽  
Vol 190 (1) ◽  
pp. 251-263 ◽  
Author(s):  
Lei Li ◽  
Wei Deng ◽  
Jie Song ◽  
Wei Ding ◽  
Qun-Fei Zhao ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Biosynthetic Gene Cluster ◽  
Nonribosomal Peptide Synthetase ◽  
Combinatorial Biosynthesis ◽  
Common Mechanism ◽  
Nonribosomal Peptide ◽  
Streptomyces Lavendulae ◽  
Peptide Synthetase

ABSTRACT Saframycin A (SFM-A), produced by Streptomyces lavendulae NRRL 11002, belongs to the tetrahydroisoquinoline family of antibiotics, and its core is structurally similar to the core of ecteinascidin 743, which is a highly potent antitumor drug isolated from a marine tunicate. In this study, the biosynthetic gene cluster for SFM-A was cloned and localized to a 62-kb contiguous DNA region. Sequence analysis revealed 30 genes that constitute the SFM-A gene cluster, encoding an unusual nonribosomal peptide synthetase (NRPS) system and tailoring enzymes and regulatory and resistance proteins. The results of substrate prediction and in vitro characterization of the adenylation specificities of this NRPS system support the hypothesis that the last module acts in an iterative manner to form a tetrapeptidyl intermediate and that the colinearity rule does not apply. Although this mechanism is different from those proposed for the SFM-A analogs SFM-Mx1 and safracin B (SAC-B), based on the high similarity of these systems, it is likely they share a common mechanism of biosynthesis as we describe here. Construction of the biosynthetic pathway of SFM-Y3, an aminated SFM-A, was achieved in the SAC-B producer (Pseudomonas fluorescens). These findings not only shed new insight on tetrahydroisoquinoline biosynthesis but also demonstrate the feasibility of engineering microorganisms to generate structurally more complex and biologically more active analogs by combinatorial biosynthesis.

Asymmetric synthesis and in vivo/in vitro characterization of new hybrid anticonvulsants derived from (2,5-dioxopyrrolidin-1-yl)phenylacetamides

2021 ◽  
Vol 109 ◽  
pp. 104751
Author(s):  
Michał Abram ◽  
Anna Rapacz ◽  
Gniewomir Latacz ◽  
Bartłomiej Szulczyk ◽  
Justyna Kalinowska-Tłuścik ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
In Vitro Characterization

scholarly journals In vivo and in vitro characterization of overproduced colicin E9 immunity protein

1992 ◽  
Vol 207 (2) ◽  
pp. 687-695 ◽  
Author(s):  
Russell WALLIS ◽  
Ann REILLY ◽  
Arthur ROWE ◽  
Geoffrey R. MOORE ◽  
Richard JAMES ◽  
...  
Keyword(s):  
Immunity Protein ◽  
In Vitro Characterization ◽  
Colicin E9

scholarly journals Identification of a Novel Delta Opioid Receptor Agonist Chemotype with Potential Negative Allosteric Modulator Capabilities

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7236
Author(s):  
Yazan J. Meqbil ◽  
Hongyu Su ◽  
Robert J. Cassell ◽  
Kendall L. Mores ◽  
Anna M. Gutridge ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Clinical Drug Development ◽  
In Vitro Characterization ◽  
Opioid Receptor Agonist ◽  
Negative Allosteric Modulator ◽  
Δ Opioid Receptor ◽  
Clinical Drug

The δ-opioid receptor (δOR) holds great potential as a therapeutic target. Yet, clinical drug development, which has focused on δOR agonists that mimic the potent and selective tool compound SNC80 have largely failed. It has increasingly become apparent that the SNC80 scaffold carries with it potent and efficacious β-arrestin recruitment. Here, we screened a relatively small (5120 molecules) physical drug library to identify δOR agonists that underrecruit β-arrestin, as it has been suggested that compounds that efficaciously recruit β-arrestin are proconvulsant. The screen identified a hit compound and further characterization using cellular binding and signaling assays revealed that this molecule (R995045, compound 1) exhibited ten-fold selectivity over µ- and κ-opioid receptors. Compound 1 represents a novel chemotype at the δOR. A subsequent characterization of fourteen analogs of compound 1, however did not identify a more potent δOR agonist. Computational modeling and in vitro characterization of compound 1 in the presence of the endogenous agonist leu-enkephalin suggest compound 1 may also bind allosterically and negatively modulate the potency of Leu-enkephalin to inhibit cAMP, acting as a ‘NAM-agonist’ in this assay. The potential physiological utility of such a class of compounds will need to be assessed in future in vivo assays.

In vivo and in vitro characterization of rifampicine suppositories

2009 ◽  
Vol 19 (3) ◽  
pp. 217-221
Author(s):  
H.M. El-Nahas ◽  
F.S. Ghazy ◽  
H.A. El-Ghamry ◽  
A.M. El-Wsaby
Keyword(s):  
In Vitro Characterization

Genetic localization and in vivo characterization of a Monascus azaphilone pigment biosynthetic gene cluster

2013 ◽  
Vol 97 (14) ◽  
pp. 6337-6345 ◽  
Author(s):  
Bijinu Balakrishnan ◽  
Suman Karki ◽  
Shih-Hau Chiu ◽  
Hyun-Ju Kim ◽  
Jae-Won Suh ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Biosynthetic Gene Cluster ◽  
Biosynthetic Gene ◽  
Genetic Localization ◽  
In Vivo Characterization ◽  
Azaphilone Pigment

In vivo and in vitro trimethadione oxidation activity of the liver from various animal species including mouse, hamster, rat, rabbit, dog, monkey and human

1999 ◽  
Vol 18 (1) ◽  
pp. 12-16 ◽  
Author(s):  
E Tanaka ◽  
A Ishikawa ◽  
T Horie
Keyword(s):  
Animal Species ◽  
In Vitro Study ◽  
Metabolic Clearance ◽  
Oxidation Activity ◽  
In Vitro Characterization ◽  
Demethylase Activity ◽  
Total Body

Trimethadione (TMO) has the properties required of a probe drug for the evaluation of hepatic drug-oxidizing capacity and, in this study, we have summarized the in vivo and in vitro metabolism of TMO in various animal species including mouse, hamster, rat, rabbit, dog, monkey and human. In the in vivo study, the plasma TMO level was measured after intravenous or oral (human) administration of TMO at a dose of 4 mg/kg to various animal species. The rate of TMO metabolic clearance in these animal species in vivo was in the order mouse > hamster >rat>rabbit>dog>monkey>human. In the in vitro study, species differences were observed in the cytochrome P450 (P450) content and drug-oxidizing enzyme activity. The content of P450 was monkey> mouse>dog>rabbit>hamster>rat>human. On the other hand, TMO N-demethylation was in the order mouse >hamster >rat >rabbit>dog>monkey>human. There was a good correlation between the mean total body clearance of TMO ( in vivo)andthemeanTMON-demethylase activity ( in vitro) (y=1.7×+0.11, r=0.965, P<0.001). These results show that TMO is a probe agent with metabolic and pharmacokinetic characteristics making it attractive for the in vivo and in vitro characterization of metabolic activity in various animal species.

In vitro characterization of PRRSV isolates with different in vivo virulence using monocyte-derived macrophages

2019 ◽  
Vol 231 ◽  
pp. 139-146 ◽  
Author(s):  
Giulia Ogno ◽  
Carmen A. Sautter ◽  
Elena Canelli ◽  
Obdulio García-Nicolás ◽  
Tomasz Stadejek ◽  
...  
Keyword(s):  
In Vitro Characterization
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