RESUMEN

We have cloned the genes encoding the chaperones of Meiothermus ruber, Hsp70 (Mru.Hsp70), Hsp40 (Mru.Hsp40) and Hsp22 (Mru.Hsp22). The genes hsp70, hsp22 and hsp40 of M. ruber are organized into an operon. The amino acid sequences of the three M. ruber chaperones show strong similarity with the heat shock proteins of Thermus thermophilus. Both Mru.Hsp40 and its homolog from T. thermophilus lack a cysteine-rich region. However, recombinant Mru.Hsp70 and Mru.Hsp40 associate in an ATP-dependent manner, and assemble into a complex in the absence of other proteins, unlike their counterparts from T. thermophilus, which require DafA for assembly. The analysis revealed that Mru.Hsp70 and Mru.Hsp40 assemble as monomers into the complex, although their homologs from T. thermophilus enter the complex as trimers. The Mru.Hsp70 and Mru.Hsp40 complex increases the spontaneous rate of refolding of denatured mitochondrial malate dehydrogenase by tenfold.

Asunto(s)

Genes Bacterianos/genética , Proteínas HSP70 de Choque Térmico/química , Proteínas HSP70 de Choque Térmico/genética , Thermus/química , Thermus/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN Bacteriano/química , ADN Bacteriano/genética , Expresión Génica , Proteínas HSP70 de Choque Térmico/metabolismo , Datos de Secuencia Molecular , Operón , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , Especificidad de la Especie , Thermus/clasificación , Thermus thermophilus/química , Thermus thermophilus/genética

RESUMEN

Zn(2+) and Co(2+) ions are known to promote human growth hormone reversible dimerization. In these studies, dimerization was also shown to be initiated by nine other metal ions: Cd(2+), Hg(2+), Cu(2+), Ag+, Au(3+), Au+, Pd(2+), Ni(2+), and Pt(4+). In some cases (Hg(2+), Ag(+), Au(3+), and Ni(2+)) formation of higher oligomers also took place. In addition further detailed investigation of dimerization in the presence of Zn(2+) ions was carried out.

Asunto(s)

Hormona de Crecimiento Humana/química , Metales Pesados/farmacología , Secuencia de Aminoácidos , Cationes , Reactivos de Enlaces Cruzados , Dimerización , Hormona de Crecimiento Humana/efectos de los fármacos , Humanos , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Triazinas/farmacología , Tripsina