RESUMO
BACKGROUND: Asian rust (Phakopsora pachyrhizi) is a common disease in Brazilian soybean fields and it is difficult to control. To identify a biochemical candidate with potential to combat this disease, a new chitinase-like xylanase inhibitor protein (XIP) from coffee (Coffea arabica) (CaclXIP) leaves was cloned into the pGAPZα-B vector for expression in Pichia pastoris. RESULTS: A cDNA encoding a chitinase-like xylanase inhibitor protein (XIP) from coffee (Coffea arabica) (CaclXIP), was isolated from leaves. The amino acid sequence predicts a (ß/α)8 topology common to Class III Chitinases (glycoside hydrolase family 18 proteins; GH18), and shares similarity with other GH18 members, although it lacks the glutamic acid residue essential for catalysis, which is replaced by glutamine. CaclXIP was expressed as a recombinant protein in Pichia pastoris. Enzymatic assay showed that purified recombinant CaclXIP had only residual chitinolytic activity. However, it inhibited xylanases from Acrophialophora nainiana by approx. 60% when present at 12:1 (w/w) enzyme:inhibitor ratio. Additionally, CaclXIP at 1.5 µg/µL inhibited the germination of spores of Phakopsora pachyrhizi by 45%. CONCLUSIONS: Our data suggests that CaclXIP belongs to a class of naturally inactive chitinases that have evolved to act in plant cell defence as xylanase inhibitors. Its role on inhibiting germination of fungal spores makes it an eligible candidate gene for the control of Asian rust.
Assuntos
Basidiomycota/efeitos dos fármacos , Quitinases/farmacologia , Café/enzimologia , Xilosidases/antagonistas & inibidores , Sequência de Aminoácidos , Basidiomycota/fisiologia , Quitinases/química , Quitinases/genética , Quitinases/metabolismo , Clonagem Molecular , Café/genética , Eletroforese em Gel de Poliacrilamida , Germinação/efeitos dos fármacos , Anotação de Sequência Molecular , Dados de Sequência Molecular , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/farmacologia , Alinhamento de Sequência , Glycine max/microbiologia , Esporos Fúngicos/efeitos dos fármacosRESUMO
Well-differentiated thyroid cancer most commonly presents as an intrathyroidal tumor; however, extrathyroidal extension occurs in approximately 6% to 13% of patients and carries a significant negative impact on survival. Extrathyroidal disease may involve critical structures in the central neck, including the recurrent laryngeal nerves, trachea, esophagus, and larynx, requiring surgery extending significantly beyond the thyroid gland. Appropriate surgical management is of great importance and can normalize survival curves, whereas gross residual disease postoperatively may lead to recurrence and decreased survival. Adjuvant postoperative therapies for thyroid cancers with extrathyroidal extension include thyroid hormone suppression, radioactive iodine therapy, and external beam radiotherapy. This summary reviews approaches to the management of invasive thyroid cancers involving the aerodigestive tract.
Assuntos
Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Cartilagem/patologia , Terapia Combinada , Esôfago/patologia , Humanos , Laringe/patologia , Invasividade Neoplásica , Técnicas de Sutura , Traqueia/patologia , Paralisia das Pregas VocaisRESUMO
A novel series of pyrazolo[1,5-b]pyridazines have been synthesized and identified as cyclin dependant kinase inhibitors potentially useful for the treatment of solid tumors. Modification of the hinge-binding amine or the C(2)- and C(6)-substitutions on the pyrazolopyridazine core provided potent inhibitors of CDK4 and demonstrated enzyme selectivity against VEGFR-2 and GSK3beta.