Delivery of a BET protein degrader via a CEACAM6-targeted antibody-drug conjugate inhibits tumour growth in pancreatic cancer models.

Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis of all cancers. To improve PDAC therapy, we establish screening systems based on organoid and co-culture technologies and find a payload of antibody-drug conjugate (ADC), a bromodomain and extra-terminal (BET) protein degrader named EBET. We select CEACAM6/CD66c as an ADC target and developed an antibody, #84.

Carbon-free production of 2-deoxy-scyllo-inosose (DOI) in cyanobacterium Synechococcus elongatus PCC 7942.

Owing to their photosynthetic capabilities, there is increasing interest in utilizing cyanobacteria to convert solar energy into biomass. 2-Deoxy-scyllo-inosose (DOI) is a valuable starting material for the benzene-free synthesis of catechol and other benzenoids. DOI synthase (DOIS) is responsible for the formation of DOI from d-glucose-6-phosphate (G6P) in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics such as neomycin and butirosin.

Structure of 2-deoxy-scyllo-inosose synthase, a key enzyme in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics, in complex with a mechanism-based inhibitor and NAD+.

A key enzyme in the biosynthesis of clinically important aminoglycoside antibiotics is 2-deoxy-scyllo-inosose synthase (DOIS), which catalyzes carbocycle formation from D-glucose-6-phosphate to 2-deoxy-scyllo-inosose through a multistep reaction. This reaction mechanism is similar to the catalysis by dehydroquinate synthase (DHQS) of the cyclization of 3-deoxy-D-arabino-heputulosonate-7-phosphate to dehydroquinate in the shikimate pathway, but significant dissimilarity between these enzymes is also known, particularly in the stereochemistry of the phosphate elimination reaction and the cyclization. Here, the crystal structures of DOIS from Bacillus circulans and its complex with the substrate analog inhibitor carbaglucose-6-phosphate, NAD+, and Co2+ have been determined to provide structural insights into the reaction mechanism.

Cloning of the pactamycin biosynthetic gene cluster and characterization of a crucial glycosyltransferase prior to a unique cyclopentane ring formation.

The biosynthetic gene (pct) cluster for an antitumor antibiotic pactamycin was identified by use of a gene for putative radical S-adenosylmethionine methyltransferase as a probe. The pct gene cluster is localized to a 34 kb contiguous DNA from Streptomyces pactum NBRC 13433 and contains 24 open reading frames. Based on the bioinformatic analysis, a plausible biosynthetic pathway for pactamycin comprising of a unique cyclopentane ring, 3-aminoacetophenone, and 6-methylsalicylate was proposed.

Role of glutamate 243 in the active site of 2-deoxy-scyllo-inosose synthase from Bacillus circulans.

2-Deoxy-scyllo-inosose (DOI) synthase is involved in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics and catalyzes the carbocyclic formation from d-glucose-6-phosphate (G-6-P) into DOI. The reaction mechanism is proposed to be similar to that of dehydroquinate (DHQ) synthase in the shikimate pathway, and includes oxidation of C-4, beta-elimination of phosphate, reduction of C-4, ring opening, and intramolecular aldol cyclization. To investigate the reaction mechanism of DOI synthase, site-directed mutational analysis of three presumable catalytically important amino acids of DOI synthase derived from the butirosin producer Bacillus circulans (BtrC) was carried out.

Biosynthesis of 2-deoxystreptamine-containing antibiotics in Streptoalloteichus hindustanus JCM 3268: characterization of 2-deoxy-scyllo-inosose synthase.

A part of the new biosynthetic gene cluster for 2-deoxystreptamine-containing antibiotics was identified from Streptoalloteichus hindustanus. The alloH gene in the gene cluster was deduced to encode 2-deoxy-scyllo-inosose synthase and the expressed protein AlloH was confirmed to have this enzyme activity. Furthermore, biochemical properties of AlloH were studied.