Engineering the assembly of heme cofactors in man-made proteins.

Autor: Solomon LA; The Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States., Kodali G, Moser CC, Dutton PL
Jazyk: angličtina
Zdroj: Journal of the American Chemical Society [J Am Chem Soc] 2014 Feb 26; Vol. 136 (8), pp. 3192-9. Date of Electronic Publication: 2014 Feb 13.
DOI: 10.1021/ja411845f
Abstrakt: Timely ligation of one or more chemical cofactors at preselected locations in proteins is a critical preamble for catalysis in many natural enzymes, including the oxidoreductases and allied transport and signaling proteins. Likewise, ligation strategies must be directly addressed when designing oxidoreductase and molecular transport functions in man-made, first-principle protein constructs intended to operate in vitro or in vivo. As one of the most common catalytic cofactors in biology, we have chosen heme B, along with its chemical analogues, to determine the kinetics and barriers to cofactor incorporation and bishistidine ligation in a range of 4-α-helix proteins. We compare five elementary synthetic designs (maquettes) and the natural cytochrome b562 that differ in oligomeric forms, apo- and holo-tertiary structural stability; qualities that we show can either assist or hinder assembly. The cofactor itself also imposes an assembly barrier if amphiphilicity ranges toward too hydrophobic or hydrophilic. With progressive removal of identified barriers, we achieve maquette assembly rates as fast as native cytochrome b562, paving the way to in vivo assembly of man-made hemoprotein maquettes and integration of artificial proteins into enzymatic pathways.
Databáze: MEDLINE