Publications by authors named "Mohamed Belal Hamed"

Deposition of amyloid-β (Aβ) peptides in the brain is a hallmark of Alzheimer's disease. Aβs are generated through sequential proteolysis of the amyloid precursor protein by the γ-secretase complexes (GSECs). Aβ peptide length, modulated by the Presenilin (PSEN) and APH-1 subunits of GSEC, is critical for Alzheimer's pathogenesis.

View Article and Find Full Text PDF

Background: S. lividans TK24 is a popular host for the production of small molecules and the secretion of heterologous protein. Within its large genome, twenty-nine non-essential clusters direct the biosynthesis of secondary metabolites.

View Article and Find Full Text PDF

TK24 is a relevant Gram-positive soil inhabiting bacterium and one of the model organisms of the genus . It is known for its potential to produce secondary metabolites, antibiotics, and other industrially relevant products. TK24 is the plasmid-free derivative of 66 and a close genetic relative of the strain A3(2).

View Article and Find Full Text PDF
Article Synopsis
  • The study addresses the growing issue of antibiotic resistance and focuses on targeting bacterial protein export pathways, specifically the essential Sec pathway which is unique to bacteria.
  • Researchers developed a high-throughput screening method to identify small molecule inhibitors that affect protein secretion, screening approximately 240,000 compounds and confirming 14 potential secretion inhibitors (HSIs) with low inhibitory concentrations (IC < 60 µM).
  • Seven of these HSIs were found to have bactericidal effects against both Gram-negative and Gram-positive bacteria, with HSI#6 being the most potent, suggesting these compounds could serve as promising candidates for new antibiotics.
View Article and Find Full Text PDF

Fluorescent proteins are a major cell biology tool to analyze protein sub-cellular topology. Here we have applied this technology to study protein secretion in the Gram-positive bacterium TK24, a widely used host for heterologous protein secretion biotechnology. Green and monomeric red fluorescent proteins were fused behind Sec (SP) or Tat (SP) signal peptides to direct them through the respective export pathway.

View Article and Find Full Text PDF
Article Synopsis
  • - The study investigates the potential of a new source of peroxidase from sycamore latex (POL) for antibody conjugation, comparing its properties to the widely used horseradish peroxidase (HRP).
  • - Results indicate that POL conjugates show better recovery rates, higher thermal stability, and a wider pH range than HRP conjugates, along with a demonstrated ability to bind effectively to substrates in immunoassays.
  • - The findings suggest that POL is a promising alternative for use in immunodiagnostic kits due to its superior storage stability and enzymatic activity over time.
View Article and Find Full Text PDF

Protein secretion is a central biological process in all organisms. Most studies dissecting bacterial secretion mechanisms have focused on Gram-negative cell envelopes such as that of However, proteomics analyses in Gram negatives is hampered by their outer membrane. Here we studied protein secretion in the Gram-positive bacterium TK24, in which most of the secretome is released in the growth medium.

View Article and Find Full Text PDF

Bacteria are of tremendous importance in the pharma- and bio-industry as producers of a broad range of economically interesting metabolites and proteins. Gram-positive bacteria are valuable hosts for the production of heterologous proteins for obvious reasons. Contrary to Gram-negative bacteria, Gram-positive bacteria release their secreted proteins immediately into the spent culture broth as they are not hindered by an outer membrane.

View Article and Find Full Text PDF

Background: The gene encoding a thermostable cellulase of family 12 was previously isolated from a Rhodothermus marinus through functional screening. CelA is a protein of 260 aminoacyl residues with a 28-residue amino-terminal signal peptide. Mature CelA was poorly synthesized in some Escherichia coli strains and not at all in others.

View Article and Find Full Text PDF