Biomedical subjects

Chang Eun Yoo

Publications and source records attributed to Chang Eun Yoo.

3 recordsLinked to original sources

PubMed2003

Degradation of myoglobin by polymeric artificial metalloproteases containing catalytic modules with various catalytic group densities: site selectivity in peptide bond cleavage.

Mononuclear, dinuclear, and tetranuclear artificial metalloproteases were prepared by attaching respective catalytic modules containing the Cu(II) complex of cyclen (Cu(II)Cyc) to a derivative of cross-linked polystyrene. The polymeric artificial metalloproteases effectively cleaved peptide bonds of myoglobin (Mb) by hydrolysis. The proteolytic activity increased considerably as the catalytic group density was raised: the ratio of k(cat)/K(m) was 1:13:100 for the mono-, di-, and tetranuclear catalysts. In the degradation of Mb by the dinuclear catalyst, two pairs of intermediate proteins accumulated. One of the two initial cleavage sites leading to the formation of the protein fragments is identified as Gln(91)-Ser(92) and the other is suggested as Ala(94)-Thr(95). On the basis of a molecular modeling study by using the X-ray crystallographic structure of Mb, the site-selectivity is attributed to anchorage of one Cu(II)Cyc unit of the catalytic module to a heme carboxylate of Mb. The high site selectivity for the initial cleavage of a protein substrate and mechanistic analysis of the catalytic action are unprecedented for polymeric artificial enzymes.

Animals↗

PubMed2003

Toward protein-cleaving catalytic drugs: artificial protease selective for myoglobin.

A protein-cleaving catalyst highly selective for a disease-related protein can be used as a catalytic drug. As the first protein-cleaving catalyst selective for a protein substrate, a catalyst for myoglobin (Mb) was designed by attaching the Cu(II) or Co(III) complex of cyclen to a binding site searched by a combinatorial method using peptide nucleic acid monomers as building units. Various linkers were inserted between the catalytic Co(III) center and the binding site of the Mb-cleaving catalyst. Kinetic data revealed catalytic turnover of the Mb cleavage by the Cu(II) or Co(III) complex. MALDI-TOF MS revealed cleavage of the polypeptide backbone of Mb at selected positions. N-Terminal sequencing of the cleavage products identified the cleavage site and provided evidence for the hydrolytic nature of the Mb cleavage. Various chelating ligands were tested as the ligand for the Co(III) center of the Mb-cleaving catalyst. Among the nine chelating ligands examined, only cyclen and its triaza-monooxo analogue manifested catalytic activity.

Binding Sites↗

PubMed2002

Protein-cleaving catalyst selective for protein substrate.

A protein-cleaving catalyst specific for a disease-related protein can be used as a catalytic drug. As the first protein-cleaving catalyst selective for a protein substrate, a catalyst for myoglobin was designed by attaching Cu(II) or Co(III) complex of cyclen to a binding site searched by a combinatorial method using peptide nucleic acid monomers as building units. [reaction: see text]

Base Sequence↗