The formation of dipeptides from amino acids can be driven by hydroxyapatite at a relatively low temperature in air. For example, the formation of (Ala)2 from Ala is induced on hydroxyapatite at 110°C with consid...The formation of dipeptides from amino acids can be driven by hydroxyapatite at a relatively low temperature in air. For example, the formation of (Ala)2 from Ala is induced on hydroxyapatite at 110°C with considerable yield. Typically, condensing agents, high temperatures (>250°C) or high pressures (>25 MPa) are required to drive the condensation of amino acids. Similar effects are observed in the condensation of Gly, Glu and Asp. Experiments demonstrate that hydroxyapatite is an effective inorganic catalytic agent, reducing the activation barrier for the formation of dipeptides by more than 50%. HAP promotes condensation by adsorbing amino acid monomers in an organized manner, which decreases the distance between amino and carboxyl groups on neighboring molecules and extends the contact time of the reaction groups. This work provides a chemical understanding of the primitive condensation of amino acids and reveals a mechanism for enhancement of mineral catalysts. It is important that the conditions used for hydroxyapatite-assisted dipeptide formation are not harsh and can be readily achieved, revealing a possible mechanism for the chemical evolution of biomolecules over geologic ages.展开更多
基金supported by the National Natural Science Foundation of China (20601023 and 20871102)Zhejiang Provincial Natural Science Foundation (R407087)the Fundamental Research Funds for the Central Universities and Daming Biomineralization Foundation
文摘The formation of dipeptides from amino acids can be driven by hydroxyapatite at a relatively low temperature in air. For example, the formation of (Ala)2 from Ala is induced on hydroxyapatite at 110°C with considerable yield. Typically, condensing agents, high temperatures (>250°C) or high pressures (>25 MPa) are required to drive the condensation of amino acids. Similar effects are observed in the condensation of Gly, Glu and Asp. Experiments demonstrate that hydroxyapatite is an effective inorganic catalytic agent, reducing the activation barrier for the formation of dipeptides by more than 50%. HAP promotes condensation by adsorbing amino acid monomers in an organized manner, which decreases the distance between amino and carboxyl groups on neighboring molecules and extends the contact time of the reaction groups. This work provides a chemical understanding of the primitive condensation of amino acids and reveals a mechanism for enhancement of mineral catalysts. It is important that the conditions used for hydroxyapatite-assisted dipeptide formation are not harsh and can be readily achieved, revealing a possible mechanism for the chemical evolution of biomolecules over geologic ages.
