RESUMO
A pollen-specific gene from lily (Lilium longiflorum Thunb. cv. Snow Queen), designated LLP-PG, was characterized. Southern blots of lily genomic DNA indicated that LLP-PG is a member of a small gene family. A thorough sequence analysis revealed that the LLP-PG gene is interrupted by two introns and encodes a protein of 413 amino acids, with a calculated molecular mass of 44 kDa, and a pI of 8.1. Evaluation of the hydropathy profile showed that the protein has a hydrophobic segment at the N-terminus, indicating the presence of a putative signal peptide. A sequence similarity search showed a significant homology of the encoded protein to pollen polygalacturonases (PGs) from various plant species and to an important group (group 13) of grass pollen allergens. The LLP-PG transcript is pollen-specific and it accumulates only at the latest stage during pollen development, in the mature pollen. In contrast to other "late genes" LLP-PG transcript can neither be induced by abscisic acid (ABA) nor by dehydration. Immunoblot analyses of pollen protein extracts from lily, timothy grass and tobacco with IgG antibodies directed against LLP-PG and against the timothy grass pollen allergen, Phl p 13, indicated that lily LLP-PG shares surface-exposed epitopes with pollen PGs from monocotyledonous and dicotyledonous plants. Enzyme-linked immunosorbent assay (ELISA) analyses and inhibition ELISA assays with patients' IgE demonstrated a very low IgE reactivity of lily rLLP-PG and a lack of cross-reactivity between rLLP-PG and the timothy grass pollen allergen, rPhl p 13. These data demonstrated that despite the significant sequence homology and the conserved surface-exposed epitopes LLP-PG represents a low-allergenic member of pollen PGs.
Assuntos
Alérgenos/biossíntese , Regulação da Expressão Gênica de Plantas/fisiologia , Lilium/enzimologia , Proteínas de Plantas/biossíntese , Pólen/enzimologia , Poligalacturonase/biossíntese , Alérgenos/genética , Alérgenos/imunologia , Sequência de Bases , Reações Cruzadas/imunologia , Epitopos/biossíntese , Epitopos/genética , Epitopos/imunologia , Humanos , Hipersensibilidade/enzimologia , Hipersensibilidade/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Lilium/genética , Lilium/imunologia , Dados de Sequência Molecular , Phleum/enzimologia , Phleum/genética , Phleum/imunologia , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Pólen/genética , Pólen/imunologia , Poligalacturonase/genética , Poligalacturonase/imunologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Homologia de Sequência , Nicotiana/enzimologia , Nicotiana/genética , Nicotiana/imunologiaRESUMO
The ceramic films over metallic implant surfaces have the potential to improve implant performance with respect to implant fixation, wear, or corrosion. In this study, the electrolytic Al2O3 coatings on F-1537 Co-Cr-Mo alloy were conducted in an aqueous solution of Al(NO3)3. Through the cycle polarization test in Hank's solution, it was found that the corrosion potential and protection potential of the alumina-coated were higher than that of the uncoated, and the corrosion current density was lower. The phase transformation of A12O3 film on Co-Cr-Mo alloy annealed at 800 K revealed todlite (5Al2O3 . H2O) and thetaAl2O3 (113) preferred orientation for 20 min, and thetaAl2O3 (200) preferred orientation with eta phase for 80 min. Scanning electron microscopy/energy dispersive spectroscopy observations after the scratch tests showed that the adhesion of the alumina films on Co-Cr-Mo alloy can load a stress over the yield strength (450 MPa) of Co-Cr-Mo alloy. The wear loss of ultra-high molecular-weight polyethylene to the Al2O3-coated specimen was eight times less than that to the uncoated. It is concluded that such Al2O3-coated films on Co-Cr-Mo implant alloy exhibit excellent quality in corrosion, adhesion, and wear for the application of hip prosthesis.