Protoporphyrin IX (PPIX) is the last shared intermediate of heme and (bacterio)chlorophyll ((B)Chl) biosynthesis. Insertion of iron into PPIX by the PPIX ferrochelatase (FeCh) PpfC produces heme, whereas magnesium insertion by magnesium chelatase (MgCh) initiates (B)Chl synthesis. Chlorophototrophic organisms must regulate this biosynthetic node to ensure the correct flux of PPIX to each of these crucial tetrapyrrole products, presenting a particularly acute problem for the facultative bacteriu…

Disc Medicine's bitopertin met all Phase 3 APOLLO endpoints for EPP, showing 12.2 more pain-free light hours and 41.4% PPIX reduction vs placebo.

Mössbauer parameters of low spin six coordinate [Fe(II)(Por)L₂] and [Fe(II)(Por)LX] complexes (where Por is PPIX or a synthetic porphyrin; L is OH^-, H₂O, a nitrogenous...

Researchers have developed a new imaging pipeline that accurately measures a naturally occurring molecule in brain tumours, even amidst complex tissue properties and varying fluorescence, promising more reliable assessments for patients.

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Pursuing accelerated approval for bitopertin in EPP with protoporphyrin IX (PPIX) reduction as the surrogate endpointPlanning to submit NDA under...

Abstract Accumulation of the light-reactive heme precursor protoporphyrin IX (PPIX) in blood causes protoporphyria, a disease characterized by severe pain resul

After confirming the repeated cycling of oxidation states in the PPIX–peptide conjugates, we investigated how the oxidation state influences their self-assembly into nanostructures. To this end, we determined the optical properties, secondary structure and morphology of compounds 1 and 2 in nanoscale assemblies. To distinguish between monomeric and assembled states, we determined the critical aggregation concentrations of compounds 1 and 2 to be 59.4 µM and 114.7 µM, respectively (Supplementary Fig. 17). Thereafter, we used 200 µM peptides in all experiments to ensure the formation of nanoassemblies. Analysis of the absorption and fluorescence spectra acquired below and above the CAC showed that irradiation induces a red shift in the Soret band (π → π*) and emission spectra, together with broadening of the Q bands27. These spectral signatures indicate the transition of assembly states from predominantly H-aggregate to J-aggregate packing28 by photo-oxidation, which increases local polarity and reorganizes packing density (Supplementary Fig. 18). Transmission electron microscopy (TEM) revealed distinct morphologies for the assemblies formed from compounds 1 and 2; in the reduced state, NFs several hundred nanometers long were found (1NF), whereas, in the oxidized state, spherical NPs (2NP) with a diameter of 200 nm were observed (Fig. 3a,b). Remarkably, both...