Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Med Chem ; 63(4): 1528-1543, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-31860301

RESUMO

The orexin system, which consists of the two G protein-coupled receptors OX1 and OX2, activated by the neuropeptides OX-A and OX-B, is firmly established as a key regulator of behavioral arousal, sleep, and wakefulness and has been an area of intense research effort over the past two decades. X-ray structures of the receptors in complex with 10 new antagonist ligands from diverse chemotypes are presented, which complement the existing structural information for the system and highlight the critical importance of lipophilic hotspots and water molecules for these peptidergic GPCR targets. Learnings from the structural information regarding the utility of pharmacophore models and how selectivity between OX1 and OX2 can be achieved are discussed.


Assuntos
Antagonistas dos Receptores de Orexina/metabolismo , Receptores de Orexina/metabolismo , Sítios de Ligação , Simulação por Computador , Cristalografia por Raios X , Células HEK293 , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Antagonistas dos Receptores de Orexina/química , Receptores de Orexina/química
3.
Nat Struct Mol Biol ; 19(7): 685-692, 2012 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-22683995

RESUMO

Poly(ADP-ribose) polymerase 1 (PARP1) is a primary DNA damage sensor whose (ADP-ribose) polymerase activity is acutely regulated by interaction with DNA breaks. Upon activation at sites of DNA damage, PARP1 modifies itself and other proteins by covalent addition of long, branched polymers of ADP-ribose, which in turn recruit downstream DNA repair and chromatin remodeling factors. PARP1 recognizes DNA damage through its N-terminal DNA-binding domain (DBD), which consists of a tandem repeat of an unusual zinc-finger (ZnF) domain. We have determined the crystal structure of the human PARP1-DBD bound to a DNA break. Along with functional analysis of PARP1 recruitment to sites of DNA damage in vivo, the structure reveals a dimeric assembly whereby ZnF1 and ZnF2 domains from separate PARP1 molecules form a strand-break recognition module that helps activate PARP1 by facilitating its dimerization and consequent trans-automodification.


Assuntos
Dano ao DNA , Poli(ADP-Ribose) Polimerases/metabolismo , Dedos de Zinco , DNA/metabolismo , Dimerização , Modelos Moleculares , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/química
4.
Nucleic Acids Res ; 37(5): 1701-12, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19155274

RESUMO

Short-patch repair of DNA single-strand breaks and gaps (SSB) is coordinated by XRCC1, a scaffold protein that recruits the DNA polymerase and DNA ligase required for filling and sealing the damaged strand. XRCC1 can also recruit end-processing enzymes, such as PNK (polynucleotide kinase 3'-phosphatase), Aprataxin and APLF (aprataxin/PNK-like factor), which ensure the availability of a free 3'-hydroxyl on one side of the gap, and a 5'-phosphate group on the other, for the polymerase and ligase reactions respectively. PNK binds to a phosphorylated segment of XRCC1 (between its two C-terminal BRCT domains) via its Forkhead-associated (FHA) domain. We show here, contrary to previous studies, that the FHA domain of PNK binds specifically, and with high affinity to a multiply phosphorylated motif in XRCC1 containing a pSer-pThr dipeptide, and forms a 2:1 PNK:XRCC1 complex. The high-resolution crystal structure of a PNK-FHA-XRCC1 phosphopeptide complex reveals the basis for this unusual bis-phosphopeptide recognition, which is probably a common feature of the known XRCC1-associating end-processing enzymes.


Assuntos
Enzimas Reparadoras do DNA/química , Proteínas de Ligação a DNA/química , Monoéster Fosfórico Hidrolases/química , Fosfotransferases (Aceptor do Grupo Álcool)/química , Motivos de Aminoácidos , Sítios de Ligação , Calorimetria , Reparo do DNA , Enzimas Reparadoras do DNA/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Modelos Moleculares , Fosfopeptídeos/química , Fosfopeptídeos/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Deleção de Sequência , Proteína 1 Complementadora Cruzada de Reparo de Raio-X
5.
Protein Sci ; 15(10): 2356-65, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17008718

RESUMO

Exploitation of potential new targets for drug and vaccine development has an absolute requirement for multimilligram quantities of soluble protein. While recombinant expression of full-length proteins is frequently problematic, high-yield soluble expression of functional subconstructs is an effective alternative, so long as appropriate termini can be identified. Bioinformatics localizes domains, but doesn't predict boundaries with sufficient accuracy, so that subconstructs are typically found by trial and error. Combinatorial Domain Hunting (CDH) is a technology for discovering soluble, highly expressed constructs of target proteins. CDH combines unbiased, finely sampled gene-fragment libraries, with a screening protocol that provides "holistic" readout of solubility and yield for thousands of protein fragments. CDH is free of the "passenger solubilization" and out-of-frame translational start artifacts of fusion-protein systems, and hits are ready for scale-up expression. As a proof of principle, we applied CDH to p85alpha, successfully identifying soluble and highly expressed constructs encapsulating all the known globular domains, and immediately suitable for downstream applications.


Assuntos
Técnicas de Química Combinatória , Estrutura Terciária de Proteína , Proteínas/química , Biblioteca Gênica , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Proteínas/isolamento & purificação , Solubilidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...