scholarly journals Characterization of the Two-Component, FAD-Dependent Monooxygenase SgcC That Requires Carrier Protein-Tethered Substrates for the Biosynthesis of the Enediyne Antitumor Antibiotic C-1027

2008 ◽  
Vol 130 (20) ◽  
pp. 6616-6623 ◽  
Author(s):  
Shuangjun Lin ◽  
Steven G. Van Lanen ◽  
Ben Shen
Keyword(s):  
Carrier Protein ◽  
Antitumor Antibiotic ◽  
Two Component

scholarly journals Characterization of a Natural, Stable, Reversible and Colourful Anthocyanidin Network from Sphagnum Moss Based Mainly on the Yellow Trans-Chalcone and Red Flavylium Cation Forms

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 709
Author(s):  
Helge Berland ◽  
Øyvind M. Andersen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cell Wall ◽  
Peat Moss ◽  
Sphagnum Moss ◽  
Naturally Occurring ◽  
Two Component ◽  
Colour System ◽  
The Common ◽  
Cis And Trans

Anthocyanins with various functions in nature are one of the most important sources of colours in plants. They are based on anthocyanidins or 3-deoxyanthocyanidins having in common a C15-skeleton and are unique in terms of how each anthocyanidin is involved in a network of equilibria between different forms exhibiting their own properties including colour. Sphagnorubin C (1) isolated from the cell wall of peat moss (Sphagnum sp.) was in fairly acidic and neutral dimethyl sulfoxide characterized by nuclear magnetic resonance (NMR) and ultraviolet–visible (UV–vis) absorption techniques. At equilibrium, the network of 1 behaved as a two–component colour system involving the reddish flavylium cationic and the yellow trans–chalcone forms. The additional D- and E-rings connected to the common C15-skeleton extend the π-conjugation within the molecule and provide both bathochromic shifts in the absorption spectra of the various forms as well as a low isomerization barrier between the cis- and trans-chalcone forms. The hemiketal and cis-chalcone forms were thus not observed experimentally by NMR due to their short lives. The stable, reversible network of 1 with good colour contrast between its two components has previously not been reported for other natural anthocyanins and might thus have potential in future photochromic systems. This is the first full structural characterization of any naturally occurring anthocyanin chalcone form.

scholarly journals Kinetic Characterization of the WalRKSpn (VicRK) Two-Component System of Streptococcus pneumoniae: Dependence of WalKSpn (VicK) Phosphatase Activity on Its PAS Domain

2010 ◽  
Vol 192 (9) ◽  
pp. 2346-2358 ◽  
Author(s):  
Alina D. Gutu ◽  
Kyle J. Wayne ◽  
Lok-To Sham ◽  
Malcolm E. Winkler
Keyword(s):  
Amino Acids ◽  
Streptococcus Pneumoniae ◽  
Phosphatase Activity ◽  
Pas Domain ◽  
Kinetic Characterization ◽  
Two Component System ◽  
Histidine Kinases ◽  
Component System ◽  
Two Component

ABSTRACT The WalRK two-component system plays important roles in maintaining cell wall homeostasis and responding to antibiotic stress in low-GC Gram-positive bacteria. In the major human pathogen, Streptococcus pneumoniae, phosphorylated WalR Spn (VicR) response regulator positively controls the transcription of genes encoding the essential PcsB division protein and surface virulence factors. WalR Spn is phosphorylated by the WalK Spn (VicK) histidine kinase. Little is known about the signals sensed by WalK histidine kinases. To gain information about WalK Spn signal transduction, we performed a kinetic characterization of the WalRK Spn autophosphorylation, phosphoryltransferase, and phosphatase reactions. We were unable to purify soluble full-length WalK Spn . Consequently, these analyses were performed using two truncated versions of WalK Spn lacking its single transmembrane domain. The longer version (Δ35 amino acids) contained most of the HAMP domain and the PAS, DHp, and CA domains, whereas the shorter version (Δ195 amino acids) contained only the DHp and CA domains. The autophosphorylation kinetic parameters of Δ35 and Δ195 WalK Spn were similar [Km (ATP) ≈ 37 μM; k cat ≈ 0.10 min−1] and typical of those of other histidine kinases. The catalytic efficiency of the two versions of WalK Spn ∼P were also similar in the phosphoryltransfer reaction to full-length WalR Spn . In contrast, absence of the HAMP-PAS domains significantly diminished the phosphatase activity of WalK Spn for WalR Spn ∼P. Deletion and point mutations confirmed that optimal WalK Spn phosphatase activity depended on the PAS domain as well as residues in the DHp domain. In addition, these WalK Spn DHp domain and ΔPAS mutations led to attenuation of virulence in a murine pneumonia model.

scholarly journals Identification and Characterization of IMD-0354 as a Glutamine Carrier Protein Inhibitor in Melanoma

2021 ◽  
Author(s):  
Yongmei Feng ◽  
Gaurav Pathria ◽  
Susanne Heynen-Genel ◽  
Michael Jackson ◽  
Brian James ◽  
...  
Keyword(s):  
Carrier Protein ◽  
Protein Inhibitor ◽  
Identification And Characterization

Characterization of Sfp, aBacillus subtilisPhosphopantetheinyl Transferase for Peptidyl Carrier Protein Domains in Peptide Synthetases†

Biochemistry ◽  
1998 ◽  
Vol 37 (6) ◽  
pp. 1585-1595 ◽  
Author(s):  
Luis E. N. Quadri ◽  
Paul H. Weinreb ◽  
Ming Lei ◽  
Michiko M. Nakano ◽  
Peter Zuber ◽  
...  
Keyword(s):  
Protein Domains ◽  
Carrier Protein ◽  
Peptide Synthetases

Molecular cloning and characterization of two β-ketoacyl-acyl carrier protein synthase I genes from Jatropha curcas L.

2017 ◽  
Vol 214 ◽  
pp. 152-160 ◽  
Author(s):  
Wangdan Xiong ◽  
Qian Wei ◽  
Pingzhi Wu ◽  
Sheng Zhang ◽  
Jun Li ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Jatropha Curcas ◽  
Acyl Carrier Protein ◽  
Carrier Protein ◽  
Jatropha Curcas L
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