Maurício de Campos Araújo

A structure-based site-directed mutagenesis study on the neurolysin (EC 3.4.24.16) and thimet oligopeptidase (EC 3.4.24.15) catalysis

Neurolysin (EP24.16) and thimet oligopeptidase (EP24.15) are closely related metalloendopeptidases. Site‐directed mutagenesis of Tyr613 (EP24.16) or Tyr612 (EP24.15) to either Phe or Ala promoted a strong reduction of k cat/K M for both enzymes. These data suggest the importance of both hydroxyl group and aromatic ring at this specific position during substrate hydrolysis by these peptidases. Furthermore, the EP24.15 A607G mutant showed a k cat/K M of 2×105 M−1 s−1 for the Abz‐GFSIFRQ‐EDDnp substrate, similar to that of EP24.16 (k cat/K M=3×105 M−1 s−1) which contains Gly at the corresponding position; the wild type EP24.15 has a k cat/K M of 2.5×104 M−1 s−1 for this substrate.

The Intracellular Distribution and Secretion of Endopeptidases 24.15 415 (Ec 3.4.24.15) and 24.16 (Ec 3.4.24.16)

Endopeptidase 24.15 (EC 3.4.24.15; EP24.15) and endopeptidase 24.16 (EC 3.4.24.16; EP24.16) are enzymes involved in general peptide metabolism in mammalian cells and tissues. This review will focus on morphological and biochemical aspects related to the subcellular distribution and secretion of these homologous enzymes in the central nervous system. These are important issues for a better understanding of the functions of EP24.15 and EP24.16 within neuroendocrine systems.

Development of colors with sustainability: a comparative study between dyeing of cotton with reactive and vat dyestuffs

This study compared reactive dyestuffs and vat dyestuffs in the dyeing of cotton. We investigated the possibility of reuse of the effluent generated, the ecological costs, and the colorfastness to water, rubbing, daylight, and perspiration. The experiments with vat dyestuffs showed slight advantage in terms of ecological costs, generating less molecules of carbon dioxide than the experiments conducted with reactive dyestuffs, lower consumption of energy, and greater possibility for reuse of treated effluent. In addition, vat dyestuffs exhibited decolorization efficiency above 99% and rates of total organic carbon removal over 90% in all cases, in addition to higher values in colorfastness properties.