RESUMEN
INTRODUCTION: Pressure ulcers have adverse effects on health. Thus, early detection of damage to skin integrity is important for preventing the occurrence of pressure sores. Virgin Coconut Oil (VCO) is a nonpharmacological therapy that can be applied to overcome the problem of damage to skin integrity. Virgin coconut oil contains antioxidants and is rich in vitamin E. Meanwhile, two-hourly repositioning is a nursing intervention performed to prevent pressure ulcers. MATERIALS AND METHODS: This study aimed to evaluate the implementation of Virgin Coconut Oil and regular repositioning for preventing pressure sores. The designs used quasi experiment pretest and posttest nonequivalent control group; 86 participants were selected through a nonprobability sampling technique by consecutive sampling. RESULTS: The fundings suggest that there is a significant difference in the Braden QD scores from before and after virgin coconut oil of the intervention group and repositioning of the control group (p<0.001). CONCLUSION: Nurses are expected to be able to detect early damage to skin integrity by using the Braden QD Scale and to implement use Virgin Coconut Oil and repositioning.
RESUMEN
X-ray structures of two enzymes in the sterol/isoprenoid biosynthesis pathway have been determined in a structural genomics pilot study. Mevalonate-5-diphosphate decarboxylase (MDD) is a single-domain alpha/beta protein that catalyzes the last of three sequential ATP-dependent reactions which convert mevalonate to isopentenyl diphosphate. Isopentenyl disphosphate isomerase (IDI) is an alpha/beta metalloenzyme that catalyzes interconversion of isopentenyl diphosphate and dimethylallyl diphosphate, which condense in the next step toward synthesis of sterols and a host of natural products. Homology modeling of related proteins and comparisons of the MDD and IDI structures with two other experimentally determined structures have shown that MDD is a member of the GHMP superfamily of small-molecule kinases and IDI is similar to the nudix hydrolases, which act on nucleotide diphosphatecontaining substrates. Structural models were produced for 379 proteins, encompassing a substantial fraction of both protein superfamilies. All three enzymes responsible for synthesis of isopentenyl diphosphate from mevalonate (mevalonate kinase, phosphomevalonate kinase, and MDD) share the same fold, catalyze phosphorylation of chemically similar substrates (MDD decarboxylation involves phosphorylation of mevalonate diphosphate), and seem to have evolved from a common ancestor. These structures and the structural models derived from them provide a framework for interpreting biochemical function and evolutionary relationships.
Asunto(s)
Enzimas/genética , Genoma , Secuencia de Aminoácidos , Animales , Cristalización , Cristalografía por Rayos X , Enzimas/química , Enzimas/metabolismo , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , Homología de Secuencia de AminoácidoRESUMEN
The structure of a Nova protein K homology (KH) domain recognizing single-stranded RNA has been determined at 2.4 A resolution. Mammalian Nova antigens (1 and 2) constitute an important family of regulators of RNA metabolism in neurons, first identified using sera from cancer patients with the autoimmune disorder paraneoplastic opsoclonus-myoclonus ataxia (POMA). The structure of the third KH domain (KH3) of Nova-2 bound to a stem loop RNA resembles a molecular vise, with 5'-Ura-Cyt-Ade-Cyt-3' pinioned between an invariant Gly-X-X-Gly motif and the variable loop. Tetranucleotide recognition is supported by an aliphatic alpha helix/beta sheet RNA-binding platform, which mimics 5'-Ura-Gua-3' by making Watson-Crick-like hydrogen bonds with 5'-Cyt-Ade-3'. Sequence conservation suggests that fragile X mental retardation results from perturbation of RNA binding by the FMR1 protein.
Asunto(s)
Antígenos de Neoplasias , Autoantígenos/química , Síndrome del Cromosoma X Frágil/etiología , Proteínas del Tejido Nervioso/química , Síndromes Paraneoplásicos del Sistema Nervioso/etiología , Proteínas de Unión al ARN/química , Ribonucleoproteínas/química , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Sitios de Unión , Cristalografía por Rayos X , Ribonucleoproteína Heterogénea-Nuclear Grupo K , Modelos Moleculares , Datos de Secuencia Molecular , Antígeno Ventral Neuro-Oncológico , Estructura Terciaria de Proteína , Homología de Secuencia de AminoácidoRESUMEN
BACKGROUND: Nova-1 and Nova-2 are related neuronal proteins that were initially cloned using antisera obtained from patients with the autoimmune neurological disease paraneoplastic opsoclonus-myoclonus ataxia (POMA). Both of these disease gene products contain three RNA-binding motifs known as K-homology or KH domains, and their RNA ligands have been identified via binding-site selection experiments. The KH motif structure has been determined previously using NMR spectroscopy, but not using X-ray crystallography. Many proteins contain more than one KH domain, yet there is no published structural information regarding the behavior of such multimers. RESULTS: We have obtained the first X-ray crystallographic structures of KH-domain-containing proteins. Structures of the third KH domains (KH3) of Nova-1 and Nova-2 were determined by multiple isomorphous replacement and molecular replacement at 2.6 A and 2.0 A, respectively. These highly similar RNA-binding motifs form a compact protease-resistant domain resembling an open-faced sandwich, consisting of a three-stranded antiparallel beta sheet topped by three alpha helices. In both Nova crystals, the lattice is composed of symmetric tetramers of KH3 domains that are created by two dimer interfaces. CONCLUSIONS: The crystal structures of both Nova KH3 domains are similar to the previously determined NMR structures. The most significant differences among the KH domains involve changes in the positioning of one or more of the alpha helices with respect to the betasheet, particularly in the NMR structure of the KH1 domain of the Fragile X disease protein FMR-1. Loop regions in the KH domains are clearly visible in the crystal structure, unlike the NMR structures, revealing the conformation of the invariant Gly-X-X-Gly segment that is thought to participate in RNA-binding and of the variable region. The tetrameric arrangements of the Nova KH3 domains provide insights into how KH domains may interact with each other in proteins containing multiple KH motifs.