Efficient silica synthesis from tetra(glycerol)orthosilicate with cathepsin- and silicatein-like proteins

Silicateins play a key role in biosynthesis of spicules in marine sponges; they are also capable to catalyze formation of amorphous silica in vitro. Silicateins are highly homologous to cathepsins L - a family of cysteine proteases. Molecular mechanisms of silicatein activity remain controversial. Here site-directed mutagenesis was used to clarify significance of selected residues in silica polymerization. A number of mutations were introduced into two sponge proteins - silicatein A1 and cathepsin L from Latrunculia oparinae, as well as into human cathepsin L. First direction was alanine scanning of the proposed catalytic residues. Also, reciprocal mutations were introduced at selected positions that differ between cathepsins L and silicateins. Surprisingly, all the wild type and mutant proteins were capable to catalyze amorphous silica formation with a water-soluble silica precursor tetra(glycerol)orthosilicate. Some mutants possessed several-fold enhanced silica-forming activity and can potentially be useful for nanomaterial synthesis applications. Our findings contradict to the previously suggested mechanisms of silicatein action via a catalytic triad analogous to that in cathepsins L. Instead, a surface-templated biosilification by silicateins and related proteins can be proposed.

Medienart:

E-Artikel

Erscheinungsjahr:

2018

Erschienen:

2018

Enthalten in:

Zur Gesamtaufnahme - volume:8

Enthalten in:

Scientific reports - 8(2018), 1 vom: 13. Nov., Seite 16759

Sprache:

Englisch

Beteiligte Personen:

Povarova, Natalia V [VerfasserIn]
Barinov, Nikolay A [VerfasserIn]
Baranov, Mikhail S [VerfasserIn]
Markina, Nadezhda M [VerfasserIn]
Varizhuk, Anna M [VerfasserIn]
Pozmogova, Galina E [VerfasserIn]
Klinov, Dmitry V [VerfasserIn]
Kozhemyako, Valery B [VerfasserIn]
Lukyanov, Konstantin A [VerfasserIn]

Links:

Volltext

Themen:

7631-86-9
Cathepsin L
Cathepsins
EC 3.4.-
EC 3.4.22.15
Glycerol
Journal Article
PDC6A3C0OX
Research Support, Non-U.S. Gov't
Silicatein alpha
Silicates
Silicon Dioxide

Anmerkungen:

Date Completed 01.11.2019

Date Revised 01.11.2019

published: Electronic

Citation Status MEDLINE

doi:

10.1038/s41598-018-34965-9

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM290576318