RESUMO
Cucumber mosaic virus (CMV) is a damaging pathogen of over 200 mono- and dicotyledonous crop species worldwide. It has the broadest known host range of any virus, but the timescale of its evolution is unknown. To investigate the evolutionary history of this virus, we obtained the genomic sequences of 40 CMV isolates from brassicas sampled in Iran, Turkey and Japan, and combined them with published sequences. Our synonymous ('silent') site analyses revealed that the present CMV population is the progeny of a single ancestor existing 1550-2600 years ago, but that the population mostly radiated 295-545 years ago. We found that the major CMV lineages are not phylogeographically confined, but that recombination and reassortment is restricted to local populations and that no reassortant lineage is more than 251 years old. Our results highlight the different evolutionary patterns seen among viral pathogens of brassica crops across the world.
Assuntos
Brassica/virologia , Cucumovirus/genética , Evolução Molecular , Genoma Viral/genética , Sequência de Bases , Evolução Biológica , Cucumovirus/crescimento & desenvolvimento , Cucumovirus/isolamento & purificação , Genética Populacional , Irã (Geográfico) , Japão , Filogenia , Doenças das Plantas/virologia , Folhas de Planta/virologia , RNA Viral/genética , Vírus Reordenados/genética , Recombinação Genética , Alinhamento de Sequência , Análise de Sequência de RNA , TurquiaRESUMO
Matrix metalloproteinase-2 (MMP-2) is an attractive target for the diagnosis of cancer and atherosclerosis in nuclear imaging. A cyclic decapeptide, cCTTHWGFTLC (cCTT), has been used as the mother compound for the development of MMP-2-imaging agents with high potency and selectivity. Most of radiolabeled derivatives of cCTT currently developed for in vivo studies of MMP-2, however, suffer from low accumulation in the target tissues, such as tumors. For enhanced in vivo stability and tissue penetration, we designed a linear beta-tetrapeptide analog, H-beta 3-Phe-beta-Ala-beta 3-Trp-beta 3-His-OH (1), to mimic cCTT. The component beta-amino acids were prepared by reduction of N-protected alpha-amino acid methyl esters to the alcohols, followed by conversion into the cyanides, and subsequent hydrolysis. Compound 1 was obtained from these beta-amino acids by the conventional solution method. In MMP-2 inhibition assay, compound 1 displayed desirably significant inhibition, which was comparable to cCTT. These findings suggest that compound 1 may serve as a mother compound in the design and development of in vivo MMP-2-imaging agents.