Biomedical subjects

N Montanini

Publications and source records attributed to N Montanini.

5 recordsLinked to original sources

PubMed1997

Targeted screening for elongation factor Tu binding antibiotics.

The development of a screen targeted to antibiotics which bind elongation factor Tu (EF-Tu) is described. The method was based on selection of antimicrobial activities which were antagonized by exogenous EF-Tu. Kirromycin, a known inhibitor of EF-Tu, was positive in this screen. Among 47,000 microorganisms screened, several producers of kirromycin-type antibiotics were detected and the novel antibiotics GE2270 and GE37468 were discovered. These thiopeptide molecules constitute, along with amithiamycin, a novel class of antibiotics acting on EF-Tu.

Actinomycetales↗

PubMed1997

Inhibitors of type-I interleukin-1 receptor from microbial metabolites.

We describe here the results of a screening program conducted to discover inhibitors of the type-I interleukin-1 receptor (IL-1RI) from samples of microbial origin. An innovative approach, based on automated, nonradioactive receptor binding assays has been employed. Specially prepared cell-free systems have allowed the use of high concentrations of microbial metabolites in the reaction mixtures with a low percentage of false positives. More than 30,000 microbial samples from different species of soil isolates have been tested and two interesting activities have been purified and characterized. One of these, isolated from Streptomyces sp. GE48009, was identified as niphimycin, an antifungal agent also known as scopafungin. Preliminary evidence suggests that this molecule and azalomycin F, a structural analogue, inhibit IL-IRI by virtue of their long-chain guanidinium moiety. The other activity, isolated from Aspergillus sp. GE49752, was identified as flavipin, a substituted o-phthalaldehyde.

Anti-Bacterial Agents↗

PubMed1995

Bioconversion capacity of Streptomyces sp GE44282, a producer of the antibiotics heneicomycin and aurodox.

Streptomyces sp GE44282 was isolated in the course of a screening program for novel antibiotics. It co-produces heneicomycin and aurodox, two kirromycin-type antibiotics, which differ by the presence of an hydroxyl group at the C30 position of aurodox. Heneicomycin is converted into aurodox both by growing and resting cells of Streptomyces sp GE44282 and by the producer of aurodox, Streptomyces goldiniensis ATCC 21386. This bioconversion of heneicomycin is substrate-specific and is not observed using the producer of heneicomycin, Streptomyces filippiniensis NRRL 11044. The three strains show very similar taxonomic characteristics. These results suggest that heneicomycin is a precursor of aurodox, the production of which depends on the bioconversion capability expressed by the strain.

Aurodox↗

PubMed1995

Antibiotic GE37468 A: a new inhibitor of bacterial protein synthesis. I. Isolation and characterization.

GE37468 A is a new thiazolyl peptide antibiotic obtained by fermentation of Streptomyces sp. strain ATCC 55365. It inhibits bacterial protein synthesis by acting on elongation factor Tu and is structurally and functionally related to the GE2270 class of EF-Tu inhibitors. It is active in vitro against Gram-positive bacteria and Bacteroides fragilis, and protects mice against Staphylococcus aureus infection.

Animals↗

PubMed1991

Antibiotic GE2270 a: a novel inhibitor of bacterial protein synthesis. I. Isolation and characterization.

A novel antibiotic, GE2270 A, was isolated from the fermentation broth of a strain of Planobispora rosea. The product was found to inhibit bacterial protein synthesis. Structural characteristics showed similarities between GE2270 A and thiazolyl peptides such as micrococcin which is known to inhibit protein synthesis by acting directly on the ribosome. Despite this similarity GE2270 A showed functional analogy to kirromycin-like antibiotics and pulvomycin, as its molecular target was found to be elongation factor Tu (EF-Tu). GE2270 A is active against Gram-positive microorganism and anaerobes and differs from the other EF-Tu inhibitors in its spectrum of antimicrobial activity.

Actinomycetales↗