Pectin methylesterase activity is required for RALF1 peptide signalling output.

The extracellular matrix plays an integrative role in cellular responses in plants, but its contribution to the signalling of extracellular ligands largely remains to be explored. Rapid alkalinisation factors (RALFs) are extracellular peptide hormones that play pivotal roles in various physiological processes. Here, we address a crucial connection between the de-methylesterification machinery of the cell wall component pectin and RALF1 activity.

A new silicon phthalocyanine dye induces pyroptosis in prostate cancer cells during photoimmunotherapy.

Photoimmunotherapy (PIT) combines the specificity of antibodies with the cytotoxicity of light activatable photosensitizers (PS) and is a promising new cancer therapy. We designed and synthesized, in a highly convergent manner, the silicon phthalocyanine dye WB692-CB2, which is novel for being the first light-activatable PS that can be directly conjugated via a maleimide linker to cysteines. In the present study we conjugated WB692-CB2 to a humanized antibody with engineered cysteines in the heavy chains that specifically targets the prostate-specific membrane antigen (PSMA).

Photoimmunotherapy of HER2-expressing Breast Cancer Cells.

Background/aim: Breast cancer (BC) is the most common malignant disease worldwide. Localized stages of BC can be successfully treated by surgery. However, local recurrence occurs in about 4-10% of patients, requiring systemic treatments that impair the patients' quality of life and shortens life expectancy.

Photoimmunotherapy of Prostate Cancer With Antibody and Fab Fragments Targeting the Prostate Specific Membrane Antigen.

Background/aim: The standard treatment for localized prostate cancer involves surgical removal of the prostate with curative intent. However, when tumor cells persist in the operation site, there is high risk of local recurrence and tumor spread, leading to stressful follow-up treatments, impaired quality of life, and reduced overall survival. This study examined photoimmunotherapy (PIT) as a new treatment option for prostate cancer cells.

Antibody-dye Conjugates Targeting EGFR and HER2 for the Photoimmunotherapy of Bladder Cancer.

Background/aim: Although there are curative treatment options for non-muscle-invasive bladder cancer, the recurrence of this tumor is high. Therefore, novel targeted therapies are needed for the complete removal of bladder cancer cells in stages of localized disease, in order to avoid local recurrence, to spare bladder cancer patients from stressful and expensive treatment procedures and to increase their quality of life and life expectancy. This study tested a new approach for the photoimmunotherapy (PIT) of bladder cancer.

Designed membrane protein heterodimers and control of their affinity by binding domain and membrane linker properties.

Many membrane proteins utilize dimerization to transmit signals across the cell membrane regulation of the lateral binding affinity. The complexity of natural membrane proteins hampers the understanding of this regulation on a biophysical level. We designed simplified membrane proteins from well-defined soluble dimerization domains with tunable affinities, flexible linkers, and an inert membrane anchor.

Thiazolopyrimidine inhibitors of 2-methylerythritol 2,4-cyclodiphosphate synthase (IspF) from Mycobacterium tuberculosis and Plasmodium falciparum.

A library of 40,000 compounds was screened for inhibitors of 2-methylerythritol 2,4-cyclodiphosphate synthase (IspF) protein from Arabidopsis thaliana using a photometric assay. A thiazolopyrimidine derivative resulting from the high-throughput screen was found to inhibit the IspF proteins of Mycobacterium tuberculosis, Plasmodium falciparum, and A. thaliana with IC(50) values in the micromolar range.

Cross-talk between type three secretion system and metabolism in Yersinia.

Pathogenic yersiniae utilize a type three secretion system (T3SS) to inject Yop proteins into host cells in order to undermine their immune response. YscM1 and YscM2 proteins have been reported to be functionally equivalent regulators of the T3SS in Yersinia enterocolitica. Here, we show by affinity purification, native gel electrophoresis and small angle x-ray scattering that both YscM1 and YscM2 bind to phosphoenolpyruvate carboxylase (PEPC) of Y.

Inhibitors of the kinase IspE: structure-activity relationships and co-crystal structure analysis.

Enzymes of the non-mevalonate pathway for isoprenoid biosynthesis are therapeutic targets for the treatment of important infectious diseases. Whereas this pathway is absent in humans, it is used by plants, many eubacteria and apicomplexan protozoa, including major human pathogens such as Plasmodium falciparum and Mycobacterium tuberculosis. Herein, we report on the design, preparation and biological evaluation of a new series of ligands for IspE protein, a kinase from this pathway.

Biosynthesis of isoprenoids: studies on the mechanism of 2C-methyl-D-erythritol-4-phosphate synthase.

2C-Methyl-D-erythritol-4-phosphate synthase, encoded by the ispC gene (also designated dxr), catalyzes the first committed step in the nonmevalonate isoprenoid biosynthetic pathway. The reaction involves the isomerization of 1-deoxy-D-xylulose 5-phosphate, giving a branched-chain aldose derivative that is subsequently reduced to 2C-methyl-D-erythritol 4-phosphate. The isomerization step has been proposed to proceed as an intramolecular rearrangement or a retroaldol-aldol sequence.

Characterization of Aquifex aeolicus 4-diphosphocytidyl-2C-methyl-d-erythritol kinase - ligand recognition in a template for antimicrobial drug discovery.

4-Diphosphocytidyl-2C-methyl-D-erythritol kinase (IspE) catalyses the ATP-dependent conversion of 4-diphosphocytidyl-2C-methyl-D-erythritol (CDPME) to 4-diphosphocytidyl-2C-methyl-d-erythritol 2-phosphate with the release of ADP. This reaction occurs in the non-mevalonate pathway of isoprenoid precursor biosynthesis and because it is essential in important microbial pathogens and absent from mammals it represents a potential target for anti-infective drugs. We set out to characterize the biochemical properties, determinants of molecular recognition and reactivity of IspE and report the cloning and purification of recombinant Aquifex aeolicus IspE (AaIspE), kinetic data, metal ion, temperature and pH dependence, crystallization and structure determination of the enzyme in complex with CDP, CDPME and ADP.

Synthesis and characterization of cytidine derivatives that inhibit the kinase IspE of the non-mevalonate pathway for isoprenoid biosynthesis.

The enzymes of the non-mevalonate pathway for isoprenoid biosynthesis are attractive targets for the development of novel drugs against malaria and tuberculosis. This pathway is used exclusively by the corresponding pathogens, but not by humans. A series of water-soluble, cytidine-based inhibitors that were originally designed for the fourth enzyme in the pathway, IspD, were shown to inhibit the subsequent enzyme, the kinase IspE (from Escherichia coli).

Isoprenoid biosynthesis in plants - 2C-methyl-D-erythritol-4-phosphate synthase (IspC protein) of Arabidopsis thaliana.

The ispC gene of Arabidopsis thaliana was expressed in pseudomature form without the putative plastid-targeting sequence in a recombinant Escherichia coli strain. The recombinant protein was purified by affinity chromatography and was shown to catalyze the formation of 2C-methyl-D-erythritol 4-phosphate from 1-deoxy-D-xylulose 5-phosphate at a rate of 5.6 micromol x min(-1) x mg(-1) (k(cat) 4.