The Structure And Synthetic Capabilities Of A Catalytic Peptide Formed By Substrate-Directed Mechanism Implications To Prebiotic Catalysis

Details The Structure And Synthetic Capabilities Of A Catalytic Peptide Formed By Substrate-Directed Mechanism Implications To Prebiotic Catalysis The Structure And Synthetic Capabilities Of A Catalytic Peptide Formed By Substrate-Directed Mechanism Implications To Prebiotic Catalysis

Aug 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005oleb...35..369f&link_type=abstract

Origins of Life and Evolution of Biospheres, Volume 35, Issue 4, pp.369-382

Computer Science

Anhydrous Synthesis, Catalytic Peptides, Iron, Prebiotic Catalysis

Scientific paper

Previously, we have shown that a small substrate may serve as a template in the formation of a specific catalytic peptide, a phenomenon which might have had a major role in prebiotic synthesis of peptide catalysts. This was demonstrated experimentally by the formation of a catalytic metallo-dipeptide, Cys2-Fe2+, around o-nitrophenyl β-D-galactopyranoside (ONPG), by dicyandiamide (DCDA)-assisted condensation under aqueous conditions. This dipeptide was capable of hydrolyzing ONPG at a specific activity lower only 1000 fold than that of β galactosidase. In the present paper we use molecular modeling techniques to elucidate the structure of this catalyst and its complex with the substrate and propose a putative mechanism for the catalyst formation and its mode of action as a “mini enzyme”. This model suggests that interaction of Fe2+ ion with ONPG oxygens and with two cysteine SH groups promotes the specific formation of the Cys2-Fe2+ catalyst. Similarly, the interaction of the catalyst with ONPG is mediated by its Fe2+ with the substrate oxygens, leading to its hydrolysis. In addition, immobilized forms of the catalyst were synthesized on two carriers Eupergit C and amino glass beads. These preparations were capable of catalyzing the formation of ONPG from β-D-galactose and o-nitrophenol (ONP) under anhydrous conditions. The ability of the catalyst to synthesize the substrate that mediates its own formation creates an autocatalytic cycle where ONPG catalyzes the formation of a catalyst which, in turn, catalyzes ONPG formation. Such autocatalytic cycle can only operate by switching between high and low water activity conditions, such as in tidal pools cycling between wet and dry environments. Implications of the substrate-dependent formation of catalytically active peptides to prebiotic processes are discussed

Affiliated with

Also associated with

No associations

Rating

The Structure And Synthetic Capabilities Of A Catalytic Peptide Formed By Substrate-Directed Mechanism Implications To Prebiotic Catalysis does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Structure And Synthetic Capabilities Of A Catalytic Peptide Formed By Substrate-Directed Mechanism Implications To Prebiotic Catalysis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Structure And Synthetic Capabilities Of A Catalytic Peptide Formed By Substrate-Directed Mechanism Implications To Prebiotic Catalysis will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-797608