Towards an understanding of (bio)silicification: the role of amino acids and lysine oligomers in silicification

摘要: In order to understand the role that proteins play in generation of well regulated biosilica structures we need contribution components, singly and combination. To this end have performed a systematic study effect amino acids small peptide oligomers on silica formation from aqueous solution. Silicas produced potassium silicon catecholate salt at ca. pH 7 presence (Gly, Arg, Asn, Gln, Glx, Ser, Thr, Tyr, Pro, Ala, Lys) 2 Si : 1 acid molar ratio shown these affect kinetics oligomer formation, growth aggregate morphology surface properties silicas produced. The effects seen during early stages carry through particles aggregates after extended periods reaction. behaviour relates pI hydrophobicity individual acids. nitrogen containing generates larger hydroxyl hydrophobic groups with smaller than are for absence An extensive number lysine glycine units per was also (for lysine, 1–5 150 glycine, 1,4,5). Increasing additive molecule had little kinetics, aggregation, sample morphology, area porosity A distinct relationship between an increased rate reduction broadening pore sizes observed. change over behaviour, particularly regard characteristics noted (lys) 3 (lys) 4 as being smallest size incorporated into siliceous material formed. Aggregation observed accelerate exponentially full range used. Consecutive sequences same residues were produce much sum residues, extremes mediate macroscopic morphological changes. consequences findings biosilicification discussed. It is clear all functional accessible orthosilicic final determining physical nature structure forms.