کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2828776 1162758 2011 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The interstitial crystal-nucleating sheet in molluscan Haliotis rufescens shell: A bio-polymeric composite
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شناسی مولکولی
پیش نمایش صفحه اول مقاله
The interstitial crystal-nucleating sheet in molluscan Haliotis rufescens shell: A bio-polymeric composite
چکیده انگلیسی

The interstitial green sheets in abalone shell nacre are shown to be bifacially differentiated trilaminate polymeric complexes, with glycoprotein layers sandwiching a central core containing chitin. They share some common feature with the organic matrix layers between the aragonite tablets in the nacre and the periostracum, and show similarities to the myostracum. Thus, although the green sheet is reported to be unique to the abalone shell, it represents an interesting model for the study of molluscan shell biomineralization processes. Indeed, during shell formation, prismatic and spherulitic aragonite precedes and follows the deposition of the interstitial green polymeric composite sheets, and there is evidence to suggest that these sheets demark the interruption of nacre synthesis and serve to nucleate the resumption of calcium carbonate crystal growth. The green polymeric interstitial sheet purified from the abalone shell was investigated by spectroscopic and imaging techniques: FTIR, confocal microscopy, scanning and transmission electron microscopy, and by pyrolysis combined with GC–MS. Structural and compositional differences are observed between the surfaces of the two sides of the interstitial polymeric composite sheets. Moreover, comparative crystallization experiments on the green sheet sides also reveal asymmetry with respect to the nucleation of calcium carbonate. These findings suggest that these bifacially differentiated interstitial composites may play an active role in the mineral assembly processes, with one of the surfaces acting as a crystal nucleator.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Structural Biology - Volume 173, Issue 1, January 2011, Pages 128–137
نویسندگان
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