Quem veio primeiro -- o ovo ou a galinha? Pesquisadores têm resposta parcial

Computing Power Cracks Egg Shell Problem

ScienceDaily (July 12, 2010) — Researchers at the University of Warwick and the University of Sheffield have applied computing power to crack a problem in egg shell formation. The work may also give a partial answer to the age old question "what came first the chicken or the egg?"

Professor Mark Rodger from Department of Chemistry and Centre for Scientific Computing, University of Warwick (left) Dr David Quigley from the Department of Physics and Centre for Scientific Computing, University of Warwick (right). (Credit: Image courtesy of University of Warwick)

The answer to the question in this context is "chicken" or -- at least a particular chicken protein. There is however a further twist in that this particular chicken protein turns out to come both first and last. That neat trick it performs provides new insights into control of crystal growth which is key to egg shell production.

Researchers had long known that a chicken eggshell protein called ovocledidin-17 (OC-17) must play some role in egg shell formation. The protein is found only in the mineral region of the egg (the hard part of the shell) and lab bench results showed that it appeared to influence the transformation of amorphous calcium carbonate (CaCo3) into calcite crystals. The mechanism of this control remained unclear. How this process could be used to form an actual eggshell remained unclear.

University of Warwick researchers Mark Rodger and David Quigley, in collaboration with colleagues at the University of Sheffield, have now been able to apply a powerful computing tool called metadynamics and the UK national supercomputer in Edinburgh to crack this egg problem.

Dr David Quigley from the Department of Physics and Centre for Scientific Computing, University of Warwick, said: "Metadynamics extends conventional molecular dynamics (MD) simulations and is particularly good at sampling transitions between disordered and ordered states of matter."

...

Read more/Leia mais aqui: Science Daily

+++++

Angewandte Chemie International Edition
Volume 49 Issue 30, Pages 5135 - 5137

Published Online: 10 Jun 2010

Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Structural Control of Crystal Nuclei by an Eggshell Protein

Colin L. Freeman 2, John H. Harding 2, David Quigley 1, P. Mark Rodger, Prof. 1 *
1Department of Chemistry and Centre for Scientific Computing, University of Warwick, Coventry, CV4 7AL (UK)
2Department of Engineering Materials, University of Sheffield, Sheffield, S1 3JD (UK)

email: P. Mark Rodger (p.m.rodger@warwick.ac.uk)

*Correspondence to P. Mark Rodger, 1Department of Chemistry and Centre for Scientific Computing, University of Warwick, Coventry, CV4 7AL (UK)



We wish to thank the EPSRC for support under grants GR/S80103, GR/S80127, and EP/F055471/1, and Martyn Foster (Cray Research Ltd) and Ilian Todorov (Daresbury Laboratory) for help in adapting codes to HECToR. All authors contributed equally to this work.

Funded by:
EPSRC; Grant Number: GR/S80103, GR/S80127, EP/F055471/1

KEYWORDS
biomineralization • crystal growth • molecular dynamics • nanoparticles

ABSTRACT

Growing a good egg: Metadynamics simulations show that the eggshell protein ovocleidin-17 induces the formation of calcite crystals from amorphous calcium carbonate nanoparticles. Multiple spontaneous crystallization and amorphization events were simulated; these simulations suggest a catalytic cycle that explains the role of ovocleidin-17 in the first stages of eggshell formation (the picture shows one intermediate of this cycle).

Received: 4 February 2010
DIGITAL OBJECT IDENTIFIER (DOI)
10.1002/anie.201000679

+++++

Professores, pesquisadores e alunos de universidades públicas e privadas com acesso ao site CAPES/Periódicos podem ler gratuitamente este artigo do Angewandte Chemie e de mais 22.440 publicações científicas.

+++++

Vote neste blog para o prêmio TOPBLOG 2010.