6533b82afe1ef96bd128b944
RESEARCH PRODUCT
Corrosion of Heritage Objects: Collagen‐Like Triple Helix Found in the Calcium Acetate Hemihydrate Crystal Structure
Ute KolbGalina MatveevaSebastian BetteJörg StelznerThomas SchleidRobert E. DinnebierGerhard Eggertsubject
Collagen helixchemistry.chemical_elementSalt (chemistry)Crystal structureCalcium010402 general chemistry01 natural sciencesCatalysisAcetic acidchemistry.chemical_compoundchemistry.chemical_classificationcalcium010405 organic chemistryChemistryCommunicationstructure elucidationHelical StructuresGeneral Chemistrycarboxyalate ligandsCommunications0104 chemical sciencesAmino acidX-ray diffractionEfflorescenceCrystallographyTriple helixdescription
Abstract Helical motifs are common in nature, for example, the DNA double or the collagen triple helix. In the latter proteins, the helical motif originates from glycine, the smallest amino acid, whose molecular confirmation is closely related to acetic acid. The combination of acetic acid with calcium and water, which are also omnipresent in nature, materializing as calcium acetate hemihydrate, was now revealed to exhibit a collagen‐like triple helix structure. This calcium salt is observed as efflorescence phase on calcareous heritage objects, like historic Mollusca shells, pottery or marble reliefs. In a model experiment pure calcium acetate hemihydrate was crystallized on the surface of a terracotta vessel. Calcium acetate hemihydrate crystallizes in a surprisingly large unit cell with a volume of 11,794.5(3) Å3 at ambient conditions. Acetate ions bridge neighboring calcium cations forming spiral chains, which are arranged in a triple helix motif.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2020-04-01 | Angewandte Chemie (International Ed. in English) |