Mineralization of the metre-long biosilica structures of glass sponges is templated on hydroxylated collagen.
The minerals involved in the formation of metazoan skeletons principally comprise glassy silica, calcium phosphate or carbonate. Because of their ancient heritage, glass sponges (Hexactinellida) may shed light on fundamental questions such as molecular evolution, the unique chemistry and formation of the first skeletal silica-based structures, and the origin of multicellular animals. We have studied anchoring spicules from the metre-long stalk of the glass rope sponge (Hyalonema sieboldi; Porifera, Class Hexactinellida), which are remarkable for their size, durability, flexibility and optical properties. Using slow-alkali etching of biosilica, we isolated the organic fraction, which was revealed to be dominated by a hydroxylated fibrillar collagen that contains an unusual [Gly-3Hyp-4Hyp] motif. We speculate that this motif is predisposed for silica precipitation, and provides a novel template for biosilicification in nature.
Institute of Bioanalytical Chemistry, Dresden University of Technology, D-01062 Dresden, Germany. hermann.ehrlich@tu-dresden.de
Hermann
H
Ehrlich
Rainer
R
Deutzmann
Eike
E
Brunner
Enrico
E
Cappellini
Hannah
H
Koon
Caroline
C
Solazzo
Yue
Y
Yang
David
D
Ashford
Jane
J
Thomas-Oates
Markus
M
Lubeck
Carsten
C
Baessmann
Tobias
T
Langrock
Ralf
R
Hoffmann
Gert
G
Wörheide
Joachim
J
Reitner
Paul
P
Simon
Mikhail
M
Tsurkan
Aleksander V
AV
Ereskovsky
Denis
D
Kurek
Vasily V
VV
Bazhenov
Sebastian
S
Hunoldt
Michael
M
Mertig
Denis V
DV
Vyalikh
Serguei L
SL
Molodtsov
Kurt
K
Kummer
Hartmut
H
Worch
Victor
V
Smetacek
Matthew J
MJ
Collins
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D003094:Collagen / Q000737:chemistry*; D019143:Evolution, Molecular; D006900:Hydroxylation; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D011161:Porifera / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
D012822:Silicon Dioxide; D003094:Collagen