RESUMO
Asian elephant (Elephas maximus) immunity is poorly characterized and understood. This gap in knowledge is particularly concerning as Asian elephants are an endangered species threatened by a newly discovered herpesvirus known as elephant endotheliotropic herpesvirus (EEHV), which is the leading cause of death for captive Asian elephants born after 1980 in North America. While reliable diagnostic assays have been developed to detect EEHV DNA, serological assays to evaluate elephant anti-EEHV antibody responses are lacking and will be needed for surveillance and epidemiological studies and also for evaluating potential treatments or vaccines against lethal EEHV infection. Previous studies have shown that Asian elephants produce IgG in serum, but they failed to detect IgM and IgA, further hampering development of informative serological assays for this species. To begin to address this issue, we determined the constant region genomic sequence of Asian elephant IgM and obtained some limited protein sequence information for putative serum IgA. The information was used to generate or identify specific commercial antisera reactive against IgM and IgA isotypes. In addition, we generated a monoclonal antibody against Asian elephant IgG. These three reagents were used to demonstrate that all three immunoglobulin isotypes are found in Asian elephant serum and milk and to detect antibody responses following tetanus toxoid booster vaccination or antibodies against a putative EEHV structural protein. The results indicate that these new reagents will be useful for developing sensitive and specific assays to detect and characterize elephant antibody responses for any pathogen or vaccine, including EEHV.
Assuntos
Anticorpos Anti-Idiotípicos/imunologia , Betaherpesvirinae/imunologia , Elefantes/imunologia , Espécies em Perigo de Extinção , Infecções por Herpesviridae/prevenção & controle , Animais , Sequência de Bases , Cromatografia em Gel , Primers do DNA/genética , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Infecções por Herpesviridae/imunologia , Imunoglobulina A/genética , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/genética , Imunoglobulina M/imunologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Espectrometria de Massas em TandemRESUMO
Bacterial resistance to ß-lactam antibiotics caused by class B metallo-ß-lactamases (MBL), especially for certain hospital-acquired, Gram-negative pathogens, poses a significant threat to public health. We report several 2-substituted 4,5-dihydrothiazole-4-carboxylic acids to be novel MBL inhibitors. Structure activity relationship (SAR) and molecular modeling studies were performed and implications for further inhibitor design are discussed.
Assuntos
Ácidos Carboxílicos/farmacologia , Inibidores Enzimáticos/farmacologia , Tiazóis/farmacologia , Inibidores de beta-Lactamases , Ácidos Carboxílicos/síntese química , Ácidos Carboxílicos/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química , beta-Lactamases/metabolismoRESUMO
The undisputed role of His64 in proton transfer during catalysis by carbonic anhydrases in the alpha class has raised questions concerning the details of its mechanism. The highly conserved residues Tyr7, Asn62, and Asn67 in the active-site cavity function to fine tune the properties of proton transfer by human carbonic anhydrase II (HCA II). For example, hydrophobic residues at these positions favor an inward orientation of His64 and a low pK(a) for its imidazole side chain. It appears that the predominant manner in which this fine tuning is achieved in rate constants for proton transfer is through the difference in pK(a) between His64 and the zinc-bound solvent molecule. Other properties of the active-site cavity, such as inward and outward conformers of His64, appear associated with the change in DeltapK(a); however, there is no strong evidence to date that the inward and outward orientations of His64 are in themselves requirements for facile proton transfer in carbonic anhydrase.