Influence of impurity adsorption on the properties of silicon single crystal layers

Intrinsically Disordered Mollusk Shell Prismatic Protein That Modulates Calcium Carbonate Crystal Growth

“…Si wafer itself and minor peaks at 940-986 cm -1 that represent organic contaminants, such as volatile alcohols and amines adsorbed from the atmosphere and from trace compounds in our reagents. 41,42 Surprisingly, we do not observe any Raman peaks that are protein-associated (i.e., peptide backbone amide groups modes at wavenumbers >1000 cm -1 ). Thus, the mi-croRaman is not detecting an adsorbed or occluded Asprich "3" species associated with the rounded mineral deposits.…”

“…TFE has been used as a probe to confirm extrinsic stabilization capabilities of unfolded sequences via displacement of destabilizing water molecules at the peptide backbone. , As shown in Figure , the CD spectra for Asprich “3” at 0% v/v TFE at neutral pH exhibits characteristics that are typical of an IDP. Specifically, there is a major (−) ellipticity band corresponding to the π−π* transition at 198 nm that is characteristic for random coil (RC) conformation. ,,, This is not unexpected, given the polyelectrolyte nature of Asprich “3” (Figure ) and our current understanding of how polyelectrolyte domains destabilize protein structure. ,,, Comparison of this data with CD reference spectra reveals that Asprich “3” is predominantly RC (66%) and contains approximately 20−30% β-strand content, a small percentage of β-turn, and little if any α-helical content (Table ).…”

“…19,21,22,33 This is not unexpected, given the polyelectrolyte nature of Asprich "3" (Figure 1) and our current understanding of how polyelectrolyte domains destabilize protein structure. 18,19,32,41 Comparison of this data with CD reference spectra 33 reveals that Asprich "3" is predominantly RC (66%) and contains approximately 20-30% β-strand content, a small percentage of β-turn, and little if any R-helical content (Table 2).…”

“…Bulk X-ray diffraction of control and Asprich “3” assay mineral deposits confirm that various calcium carbonate polymorphs are present in Asprich “3” mineral deposits, with calcite being the predominant crystalline phase (Figure S2, Supporting Information). However, an ACC phase would not contribute to the bulk X-ray diffraction signal and thus cannot be detected using this method. ,,− With this in mind, we utilized microRaman spectroscopy to characterize the spherical deposits of the 10 and 100 μM Asprich “3” alongside the rhombohedral crystals of the control assay (Figure ), with reference to Raman spectra obtained for calcite, aragonite, and vaterite (Table ). ,, In all of the Raman spectra, we note a strong peak at 519 cm −1 that arises from the Si wafer itself and minor peaks at 940−986 cm −1 that represent organic contaminants, such as volatile alcohols and amines adsorbed from the atmosphere and from trace compounds in our reagents. , Surprisingly, we do not observe any Raman peaks that are protein-associated (i.e., peptide backbone amide groups modes at wavenumbers >1000 cm −1 ). Thus, the microRaman is not detecting an adsorbed or occluded Asprich “3” species associated with the rounded mineral deposits.…”