Biomedical subjects

A Ishikubo

Publications and source records attributed to A Ishikubo.

2 recordsLinked to original sources

PubMed1996

Dinuclear lanthanum(III) complex for efficient hydrolysis of RNA.

A dinuclear La3+ complex hydrolyzes the phosphodiester bond in diribonucleotides efficiently under mild conditions. The rate of hydrolysis is remarkably accelerated on the complex formation between La3+ and TPHP (TPHP = N,N,N',N'-tetrakis [(2-pyridyl)methyl]-2-hydroxy-1,3-diaminopropane), and the highest activity is attained when the dinuclear structure is formed. The half-life of ApA hydrolysis by the dinuclear La3+ complex (1 mM) is 350 s, whereas that by the free La3+ ion (1 mM) is 23,000 s at pH 7.2 and 50 degrees C. The dinuclear La3+ complex is promising as a catalytic center of artificial nucleases.

Binding Sites↗

PubMed1995

Dinuclear metal complexes for the efficient RNA hydrolysis.

Dinuclear Zn(II) and La(III) complexes with TPHP efficiently hydrolyze a dinucleotide, ApA, under mild conditions (TPHP = N, N, N', N'-tetrakis[(2-pyridyl)-methyl]-2-hydroxy-1,3-diaminopropane). [Zn2(TPHP)]3+ hydrolyzes ApA with an extremely high activity; The pseudo-first-order rate constant is 8.4 x 10(-4) h-1 at pH 7, 50 degrees C when [[Zn2 (TPHP)]3+] = 2.5 mM. Free Zn(II) ion shows no hydrolysis activity under the conditions. Enormous acceleration of the hydrolysis by the dinuclear complex formation was also observed for La(III) ion. Its activity for the ApA hydrolysis is 100-fold greater than that of free La(III) ion. These dinuclear complexes are promising for the active sites of artificial ribonucleases.

Binding Sites↗