Synthesis of bicyclic organo-peptide hybrids via oxime/intein-mediated macrocyclization followed by disulfide bond formation

2014 ◽  
Vol 12 (7) ◽  
pp. 1135-1142 ◽  
Author(s):  
Jessica M. Smith ◽  
Nicholas C. Hill ◽  
Peter J. Krasniak ◽  
Rudi Fasan
Keyword(s):  
Disulfide Bond ◽  
Bond Formation ◽  
Disulfide Bridge ◽  
Disulfide Bond Formation ◽  
New Strategy ◽  
Recombinant Polypeptides

A new strategy is described to convert recombinant polypeptides into bicyclic organo-peptide hybrids constrained by an intramolecular disulfide bridge.

Two dileucine motifs mediate late endosomal/lysosomal targeting of transmembrane protein 192 (TMEM192) and a C-terminal cysteine residue is responsible for disulfide bond formation in TMEM192 homodimers

2011 ◽  
Vol 434 (2) ◽  
pp. 219-231 ◽  
Author(s):  
Jörg Behnke ◽  
Eeva-Liisa Eskelinen ◽  
Paul Saftig ◽  
Bernd Schröder
Keyword(s):  
Disulfide Bond ◽  
Disulfide Bonds ◽  
Transmembrane Protein ◽  
Bond Formation ◽  
Immunogold Labelling ◽  
Disulfide Bridge ◽  
Cysteine Residue ◽  
Disulfide Bond Formation ◽  
Transmembrane Segments ◽  
Late Endosomes

TMEM192 (transmembrane protein 192) is a novel constituent of late endosomal/lysosomal membranes with four potential transmembrane segments and an unknown function that was initially discovered by organellar proteomics. Subsequently, localization in late endosomes/lysosomes has been confirmed for overexpressed and endogenous TMEM192, and homodimers of TMEM192 linked by disulfide bonds have been reported. In the present study the molecular determinants of TMEM192 mediating its transport to late endosomes/lysosomes were analysed by using CD4 chimaeric constructs and mutagenesis of potential targeting motifs in TMEM192. Two directly adjacent N-terminally located dileucine motifs of the DXXLL-type were found to be critical for transport of TMEM192 to late endosomes/lysosomes. Whereas disruption of both dileucine motifs resulted in mistargeting of TMEM192 to the plasma membrane, each of the two motifs was sufficient to ensure correct targeting of TMEM192. In order to study disulfide bond formation, mutagenesis of cysteine residues was performed. Mutation of Cys266 abolished disulfide bridge formation between TMEM192 molecules, indicating that TMEM192 dimers are linked by a disulfide bridge between their C-terminal tails. According to the predicted topology, Cys266 would be localized in the reductive milieu of the cytosol where disulfide bridges are generally uncommon. Using immunogold labelling and proteinase protection assays, the localization of the N- and C-termini of TMEM192 on the cytosolic side of the late endosomal/lysosomal membrane was experimentally confirmed. These findings may imply close proximity of the C-termini in TMEM192 dimers and a possible involvement of this part of the protein in dimer assembly.

scholarly journals Lipid Chaperoning of a Thylakoid Protease Whose Stability is Modified by the Protonmotive Force

2019 ◽  
Author(s):  
Lucas J. McKinnon ◽  
Jeremy Fukushima ◽  
Kentaro Inoue ◽  
Steven M. Theg
Keyword(s):  
Disulfide Bond ◽  
Thylakoid Membrane ◽  
Bond Formation ◽  
Disulfide Bridge ◽  
Signal Peptidase ◽  
Common Mechanism ◽  
Protonmotive Force ◽  
Type I ◽  
Disulfide Bond Formation

AbstractProtein folding is a complex cellular process often assisted by chaperones but can also be facilitated by interactions with lipids. Disulfide bond formation is a common mechanism to stabilize a protein. This can help maintain functionality amidst changes in the biochemical milieu which are especially common across energy-transducing membranes. Plastidic Type I Signal Peptidase 1 (Plsp1) is an integral thylakoid membrane signal peptidase which requires an intramolecular disulfide bond for in vitro activity. We have investigated the interplay between disulfide bond formation, lipids, and pH in the folding and activity of Plsp1. By combining biochemical approaches with a genetic complementation assay, we provide evidence that interactions with lipids in the thylakoid membrane have chaperoning activity towards Plsp1. Further, the disulfide bridge appears to prevent an inhibitory conformational change resulting from proton motive force-mimicking pH conditions. Broader implications related to the folding of proteins in energy-transducing membranes are discussed.

scholarly journals Oxygen-independent disulfide bond formation in VEGF-A and CA9

2021 ◽  
pp. 100505
Author(s):  
Fiana Levitin ◽  
Sandy Che-Eun Serena Lee ◽  
Stephanie Hulme ◽  
Ryan A. Rumantir ◽  
Amy S. Wong ◽  
...  
Keyword(s):  
Disulfide Bond ◽  
Bond Formation ◽  
Disulfide Bond Formation

scholarly journals The Sex Differences in Uveal Melanoma: Potential Roles of EIF1AX, Immune Response and Redox Regulation

2021 ◽  
Vol 28 (4) ◽  
pp. 2801-2811
Author(s):  
Feng Liu-Smith ◽  
Chi-Yang Chiu ◽  
Daniel L. Johnson ◽  
Phillip Winston Miller ◽  
Evan S. Glazer ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Sex Difference ◽  
Uveal Melanoma ◽  
Disulfide Bond ◽  
Bond Formation ◽  
Disulfide Bond Formation ◽  
Men And Women ◽  
Copy Numbers ◽  
Differential Gene

Background: Uveal melanoma (UVM) is a rare cancer that shows sex difference in incidence and survival, with little previous report for the underlying mechanism. Methods: This study used the SEER data (1974–2016) for an age-dependent analysis on sex difference in UVM, and further used the TCGA-UVM genomics dataset for analyzing the differential gene expression profiles in tumors from men and women. Results: Our results demonstrate a sex difference in older age (≥40 years) but not in younger patients, with men exhibiting a higher incidence rate than women. However, younger women have shown a continuous increasing trend since 1974. Examining the 11 major oncogenes and tumor suppressors in UVM revealed that EIF1AX showed a significant sex difference in mRNA accumulation and copy number variation, with female tumors expressing higher levels of EIF1AX and exhibiting more variations in copy numbers. EIF1AX mRNA levels were significantly inversely correlated with EIF1AX copy numbers in female tumors only, but not in male tumors. Differential gene expression analysis at the whole genomic level identified a set of 92 protein-coding and 16 RNA-coding genes which exhibited differential expression in men and women (fold of change cutoff at 1.7, adjusted p value < 0.05, FDR < 0.05). Network analysis showed significant difference in immune response and in disulfide bond formation, with EGR1/EGR2 and PDIA2 genes as regulators for immune response and disulfide bond formation, respectively. The melanocortin pathway which is linked to both melanin synthesis and obesity seems to be altered with unclear significance, as the sex difference in POMC, DCT/TYRP2, and MRAP2 was observed but with no clear direction. Conclusion: This study reveals possible mechanisms for the sex difference in tumorigenesis of UVM which has potentials for better understanding and prevention of UVM.

scholarly journals New insights into the disulfide bond formation enzymes in epidithiodiketopiperazine alkaloids

2021 ◽  
Vol 12 (11) ◽  
pp. 4132-4138
Author(s):  
Huan Liu ◽  
Jie Fan ◽  
Peng Zhang ◽  
Youcai Hu ◽  
Xingzhong Liu ◽  
...  
Keyword(s):  
Disulfide Bond ◽  
Bond Formation ◽  
Disulfide Bond Formation ◽  
Disulfide Formation

A FAD-dependent oxidoreductase TdaR was responsible for α, β-disulfide formation in the biosynthesis of pretrichodermamide A. TdaR, together with its homologs AclT and GliT, catalysed not only α, α- but also α, β-disulfide formation in fungi.

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