Molecular "tuning" of crystal growth by nacre-associated polypeptides

Il W. Kim, Molly R. Darragh, Christine Orme, John Evans

Research output: Contribution to journalArticle

Abstract

The formation and stabilization of the aragonite polymorph in the nacre layer of mollusks is an intriguing process, yet very little is known with regard to the participation of proteins in this process. Previously, we identified the 30 AA N-terminal mineral binding domains (AP7-N, AP24-N, n16-N) of three different nacre-specific proteins (AP7, AP24, n16). These three domains differ in primary sequence and induce morphological changes in CaCO3 crystals in vitro. Using AFM microscopy, we investigated the adsorption of AP7-N, AP24-N, and n16-N onto calcite dislocation hillocks. We observe that both AP7-N and AP24-N are multifunctional; they not only inhibit obtuse step advance but also induce rounded, amorphous-appearing deposits on hillock terraces. In contrast, n16-N pins corner sites at the junction of acute and obtuse steps and promote the emergence of a new set of steps approximately oriented along a line joining the obtuse-obtuse and the acute-acute corners. Random scrambling of the n16-N and AP7-N sequences resulted in substantially reduced mineral modification activities, indicating that the primary sequence of both polypeptides is crucial for correct recognition of surface features. These findings indicate that nacre proteins evolved specialized mineral interaction domains that either recognize different surface features (AP7-N, AP24-N versus n16-N), or recognize the same features, but with different binding and catalytic activities (AP24-N versus AP7-N). These functional differences may arise from the differences in primary and secondary structure specific to each N-terminal domain. Hypothetically, this molecular diversity would allow complementary and simultaneous protein control ("molecular tuning") of different features of the crystal growth process.

Original languageEnglish (US)
Pages (from-to)5-10
Number of pages6
JournalCrystal Growth and Design
Volume6
Issue number1
DOIs
StatePublished - Jan 2006

Fingerprint

Nacre
Polypeptides
polypeptides
Crystallization
Crystal growth
crystal growth
Tuning
tuning
proteins
Proteins
Minerals
Peptides
Calcium Carbonate
minerals
mollusks
aragonite
Calcite
calcite
Polymorphism
Joining

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Molecular "tuning" of crystal growth by nacre-associated polypeptides. / Kim, Il W.; Darragh, Molly R.; Orme, Christine; Evans, John.

In: Crystal Growth and Design, Vol. 6, No. 1, 01.2006, p. 5-10.

Research output: Contribution to journalArticle

Kim, Il W. ; Darragh, Molly R. ; Orme, Christine ; Evans, John. / Molecular "tuning" of crystal growth by nacre-associated polypeptides. In: Crystal Growth and Design. 2006 ; Vol. 6, No. 1. pp. 5-10.
@article{4640e7f26f9f4671945aad18c2380e0b,
title = "Molecular {"}tuning{"} of crystal growth by nacre-associated polypeptides",
abstract = "The formation and stabilization of the aragonite polymorph in the nacre layer of mollusks is an intriguing process, yet very little is known with regard to the participation of proteins in this process. Previously, we identified the 30 AA N-terminal mineral binding domains (AP7-N, AP24-N, n16-N) of three different nacre-specific proteins (AP7, AP24, n16). These three domains differ in primary sequence and induce morphological changes in CaCO3 crystals in vitro. Using AFM microscopy, we investigated the adsorption of AP7-N, AP24-N, and n16-N onto calcite dislocation hillocks. We observe that both AP7-N and AP24-N are multifunctional; they not only inhibit obtuse step advance but also induce rounded, amorphous-appearing deposits on hillock terraces. In contrast, n16-N pins corner sites at the junction of acute and obtuse steps and promote the emergence of a new set of steps approximately oriented along a line joining the obtuse-obtuse and the acute-acute corners. Random scrambling of the n16-N and AP7-N sequences resulted in substantially reduced mineral modification activities, indicating that the primary sequence of both polypeptides is crucial for correct recognition of surface features. These findings indicate that nacre proteins evolved specialized mineral interaction domains that either recognize different surface features (AP7-N, AP24-N versus n16-N), or recognize the same features, but with different binding and catalytic activities (AP24-N versus AP7-N). These functional differences may arise from the differences in primary and secondary structure specific to each N-terminal domain. Hypothetically, this molecular diversity would allow complementary and simultaneous protein control ({"}molecular tuning{"}) of different features of the crystal growth process.",
author = "Kim, {Il W.} and Darragh, {Molly R.} and Christine Orme and John Evans",
year = "2006",
month = "1",
doi = "10.1021/cg0502183",
language = "English (US)",
volume = "6",
pages = "5--10",
journal = "Crystal Growth and Design",
issn = "1528-7483",
publisher = "American Chemical Society",
number = "1",

}

TY - JOUR

T1 - Molecular "tuning" of crystal growth by nacre-associated polypeptides

AU - Kim, Il W.

AU - Darragh, Molly R.

AU - Orme, Christine

AU - Evans, John

PY - 2006/1

Y1 - 2006/1

N2 - The formation and stabilization of the aragonite polymorph in the nacre layer of mollusks is an intriguing process, yet very little is known with regard to the participation of proteins in this process. Previously, we identified the 30 AA N-terminal mineral binding domains (AP7-N, AP24-N, n16-N) of three different nacre-specific proteins (AP7, AP24, n16). These three domains differ in primary sequence and induce morphological changes in CaCO3 crystals in vitro. Using AFM microscopy, we investigated the adsorption of AP7-N, AP24-N, and n16-N onto calcite dislocation hillocks. We observe that both AP7-N and AP24-N are multifunctional; they not only inhibit obtuse step advance but also induce rounded, amorphous-appearing deposits on hillock terraces. In contrast, n16-N pins corner sites at the junction of acute and obtuse steps and promote the emergence of a new set of steps approximately oriented along a line joining the obtuse-obtuse and the acute-acute corners. Random scrambling of the n16-N and AP7-N sequences resulted in substantially reduced mineral modification activities, indicating that the primary sequence of both polypeptides is crucial for correct recognition of surface features. These findings indicate that nacre proteins evolved specialized mineral interaction domains that either recognize different surface features (AP7-N, AP24-N versus n16-N), or recognize the same features, but with different binding and catalytic activities (AP24-N versus AP7-N). These functional differences may arise from the differences in primary and secondary structure specific to each N-terminal domain. Hypothetically, this molecular diversity would allow complementary and simultaneous protein control ("molecular tuning") of different features of the crystal growth process.

AB - The formation and stabilization of the aragonite polymorph in the nacre layer of mollusks is an intriguing process, yet very little is known with regard to the participation of proteins in this process. Previously, we identified the 30 AA N-terminal mineral binding domains (AP7-N, AP24-N, n16-N) of three different nacre-specific proteins (AP7, AP24, n16). These three domains differ in primary sequence and induce morphological changes in CaCO3 crystals in vitro. Using AFM microscopy, we investigated the adsorption of AP7-N, AP24-N, and n16-N onto calcite dislocation hillocks. We observe that both AP7-N and AP24-N are multifunctional; they not only inhibit obtuse step advance but also induce rounded, amorphous-appearing deposits on hillock terraces. In contrast, n16-N pins corner sites at the junction of acute and obtuse steps and promote the emergence of a new set of steps approximately oriented along a line joining the obtuse-obtuse and the acute-acute corners. Random scrambling of the n16-N and AP7-N sequences resulted in substantially reduced mineral modification activities, indicating that the primary sequence of both polypeptides is crucial for correct recognition of surface features. These findings indicate that nacre proteins evolved specialized mineral interaction domains that either recognize different surface features (AP7-N, AP24-N versus n16-N), or recognize the same features, but with different binding and catalytic activities (AP24-N versus AP7-N). These functional differences may arise from the differences in primary and secondary structure specific to each N-terminal domain. Hypothetically, this molecular diversity would allow complementary and simultaneous protein control ("molecular tuning") of different features of the crystal growth process.

UR - http://www.scopus.com/inward/record.url?scp=31144458548&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=31144458548&partnerID=8YFLogxK

U2 - 10.1021/cg0502183

DO - 10.1021/cg0502183

M3 - Article

AN - SCOPUS:31144458548

VL - 6

SP - 5

EP - 10

JO - Crystal Growth and Design

JF - Crystal Growth and Design

SN - 1528-7483

IS - 1

ER -