RESUMO
The membrane protein bacteriorhodopsin (BR) can be kept soluble in its native state for months in the absence of detergent by amphipol (APol) A8-35, an amphiphilic polymer. After an actinic flash, A8-35-complexed BR undergoes a complete photocycle, with kinetics intermediate between that in detergent solution and that in its native membrane. BR/APol complexes form well defined, globular particles comprising a monomer of BR, a complete set of purple membrane lipids, and, in a peripheral distribution, approximately 2 g APol/g BR, arranged in a compact layer. In the absence of free APol, BR/APol particles can autoassociate into small or large ordered fibrils.
Assuntos
Bacteriorodopsinas/química , Bacteriorodopsinas/metabolismo , Polímeros/química , Polímeros/metabolismo , Propilaminas/química , Propilaminas/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Cromatografia em Gel , Coloides/química , Cor , Halobacterium salinarum/metabolismo , Lipídeos/química , Microscopia Eletrônica , Difração de Nêutrons , Estrutura Secundária de Proteína , Membrana Purpúrea/química , Membrana Purpúrea/metabolismo , Espalhamento a Baixo Ângulo , Tioglucosídeos/química , UltracentrifugaçãoRESUMO
To monitor multiple Epstein-Barr virus (EBV) infections during the early and convalescent stages of infectious mononucleosis (IM), a cloning and sequencing study of the LMP1 gene was conducted in saliva and peripheral blood mononuclear cells (PBMCs) from 23 patients with IM at day 0 (D0) and day 180 (D180) after the onset of the disease. Multiple EBV strains were detected in 9 (39%) of the patients during follow-up, with 7 of 9 cases detected as early as D0. Six of the nine patients harbored the same dominant strain in saliva and PBMCs during follow-up, with a trend toward a restriction of the number of EBV strains in saliva but not in PBMCs at D180. Furthermore, transmission of a minor strain was observed between partners in a heterosexual couple. There was no correlation between multiple infections and EBV DNA load in either compartment.
Assuntos
Herpesvirus Humano 4/genética , Herpesvirus Humano 4/isolamento & purificação , Mononucleose Infecciosa/virologia , Leucócitos Mononucleares/virologia , Saliva/virologia , Clonagem Molecular , Feminino , Genótipo , Herpesvirus Humano 4/classificação , Humanos , Mononucleose Infecciosa/transmissão , Masculino , Análise de Sequência de DNA , Carga Viral , Proteínas da Matriz Viral/genéticaRESUMO
Epstein-Barr virus (EBV) DNA loads in peripheral blood mononuclear cells (PBMCs), plasma, and saliva, as well as infectivity of the virus in saliva, were evaluated in 20 patients for 6 months after the onset of infectious mononucleosis (IM). All patients displayed sustained high EBV DNA loads in the saliva, associated with a persistent infectivity of saliva at day 180. EBV DNA load in PBMCs decreased significantly from day 0 to day 180 (in spite of a viral rebound between day 30 and day 90 in 90% of the patients), and EBV DNA rapidly disappeared from plasma. These data show that patients with IM remain highly infectious during convalescence.