Selective Recognition of Endocrine Disruptors by Fluorogenic γ-Cyclodextrin Having Pyrene-Tosyl Substituents on Hetero Rims

Narita, Minoru; Tashiro, Eiichiro; Hamada, Fumio

doi:10.2116/analsci.17.1453

Cited by 13 publications

(5 citation statements)

References 26 publications

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“…A newly developed near-field focusing plate was used for this measurement. The operation of the NFIR microscope was performed as described previously (24). The distance separating the sample and the probe was regulated by the uncontacted physical force interaction between the sample and the probe, and this distance was maintained at ϳ30 nm.…”

Section: Methodsmentioning

confidence: 99%

Calcite Formation in Soft Coral Sclerites Is Determined by a Single Reactive Extracellular Protein

Rahman

Oomori

Wörheide

2011

Journal of Biological Chemistry

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Calcium carbonate exists in two main forms, calcite and aragonite, in the skeletons of marine organisms. The primary mineralogy of marine carbonates has changed over the history of the earth depending on the magnesium/calcium ratio in seawater during the periods of the so-called "calcite and aragonite seas." Organisms that prefer certain mineralogy appear to flourish when their preferred mineralogy is favored by seawater chemistry. However, this rule is not without exceptions. For example, some octocorals produce calcite despite living in an aragonite sea. Here, we address the unresolved question of how organisms such as soft corals are able to form calcitic skeletal elements in an aragonite sea. We show that an extracellular protein called ECMP-67 isolated from soft coral sclerites induces calcite formation in vitro even when the composition of the calcifying solution favors aragonite precipitation. Structural details of both the surface and the interior of single crystals generated upon interaction with ECMP-67 were analyzed with an apertureless-type nearfield IR microscope with high spatial resolution. The results show that this protein is the main determining factor for driving the production of calcite instead of aragonite in the biocalcification process and that -OH, secondary structures (e.g. ␣-helices and amides), and other necessary chemical groups are distributed over the center of the calcite crystals. Using an atomic force microscope, we also explored how this extracellular protein significantly affects the molecular-scale kinetics of crystal formation. We anticipate that a more thorough investigation of the proteinaceous skeleton content of different calcite-producing marine organisms will reveal similar components that determine the mineralogy of the organisms. These findings have significant implications for future models of the crystal structure of calcite in nature.The primary mineralogy of marine carbonates has changed over geological history depending on the magnesium/calcium ratio in seawater, including during the so-called "aragonite sea" (1) period and two periods of "calcite seas" (2). This ratio is apparently driven by changes in spreading rates along midocean ridges (1). The calcification process of aragonite and calcite mineralogy in mollusk shells (3-8) and some information about calcite (9, 10) have been reported, but our knowledge of the mechanism of the direct biological formation of calcite in marine organisms, especially in corals, remains incomplete. To develop a more complete understanding of calcite formation, detailed information concerning how biomolecules contribute to the kinetics of crystal formation, as well as the structural details of both the surface and the interior of single crystals in the submicrometer to nanometer scale must be analyzed. The mechanism of calcite formation in soft coral sclerites that we report here is completely different from the mechanisms used by other calcifying marine organisms, featuring new chemical groups and different types of single crys...

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Section: Methodsmentioning

confidence: 99%

Calcite Formation in Soft Coral Sclerites Is Determined by a Single Reactive Extracellular Protein

Rahman

Oomori

Wörheide

2011

Journal of Biological Chemistry

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“…The operation of NFIR was performed as described in the literature. 4 The distance separating the sample and probe was regulated by an uncontacted physical force interaction between the sample and the probe, 5 and was maintained at approximately 30 nm. The probe tip oscillated parallel to the sample surface.…”

mentioning

confidence: 99%

Analysis of Protein-induced Calcium Carbonate Crystals in Soft Coral by Near-Field IR Microspectroscopy

Rahman

Oomori

2009

ANAL. SCI.

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Infrared (IR) vibrational spectroscopy is a well-established tool in materials and life-science research. This technique can obtain information regarding fundamentally important microchemical properties. Although it is widely used to analyze microchemical properties, the identification of chemical structure using vibrational spectroscopy at infrared wavelengths has been problematic because of the diffraction limits of conventional infrared microscopy, which result in low spatial resolution. For example, the spatial resolution of infrared (IR) spectroscopy is approximately 10 mm, but that of newly developed near-field IR spectra (NFIR) is 1 mm, or less. Therefore, sub-micrometer to sub-nanometer scale chemical structure analysis is difficult to achieve by conventional IR. Specifically, scientists have been hampered by difficulty to separate protein-associated small chemical compounds from biomineralized organisms. We have overcome this limitation by applying a newly developed nearfield optical technique and near-field optical microscope through NFIR with high spatial resolution. The combination of nearfield microscopy and spectroscopy enables spectra to be obtained with subwavelength spatial resolution for visible light. However, the application of the near-field optical technique to the mid-IR region has only been reported for microscopy thus far.1 The primary reason for this limitation is lack of availability of high-intensity sources and detectors for the IR region.In the present study, this technique was used with a soft coral, Lobophytum crassum, as a model calcifying organism. Soft coral is an important and integral part of marine ecosystems. It has an important role in benthic-pelagic coupling processes as a source of food for demersal grazers and predators, as a host of highly diverse microbial biomass, and as a bioeroder. Soft coral contains small spicules of calcium carbonate, called "sclerites." Sclerites can strengthen the base of the soft coral, and are used by scientists to assist in the identification of soft coral species. Sclerites are the major mineralized structures present in these organisms. To address this importance, in vitro crystallization experiments were carried out in the presence of matrix proteins extracted from sclerites.A supersaturated solution of Ca(HCO3)2 was prepared by purging a stirred aqueous suspension of CaCO3 with carbon dioxide. 2 An aragonitic solution was obtained by adding 50 mM MgCl2 to supersaturated solution. Crystallization experiments were carried out with and without the addition of 700 mg of soluble proteins (extracted from sclerites) to the solution (500 ml). The solutions were then allowed to sit for one month without further manipulation. The protein concentration in the organic matrix was measured by method of Lowry et al. 3 using chicken ovalbumin (Kanto Chemical, Tokyo, Japan) as standard. The precipitate crystals were harvested from the solution after completion of each experiment, and each sample was stored for near-field probing analysis. An aperturele...

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“…The system was described in detail in a previous paper. 25) The diameter of the tip of the probe was less than 1 mm. The distance separating the sample and probe was regulated by uncontacted physical force interaction and maintained at approximately 30 nm.…”

Section: Measurementsmentioning

confidence: 99%

“…We did not study the penetration depth of IR light into the film. However, it was reported that a near field depends on the radius of the tip of the diffraction-type probe; 25) therefore, the penetration depth was estimated to be around 1 mm. The effect of film thickness on the resolution of the recording spots will be studied in the future.…”

Section: Photochromic Recording and Nondestructive Readout Using Near...mentioning

confidence: 99%

Micrometer-Scale Photochromic Recording on Amorphous Diarylethene Film and Nondestructive Readout Using Near-Field IR Light

Takata¹,

Saito²,

Yokojima³

et al. 2006

jjap

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An amorphous photochromic recording film was prepared by spin coating a solution of a diarylethene derivative having bulky m-terphenyl groups. Near-field IR detection was carried out to read out the photochromic recording spots recorded by green laser irradiation on the film, and a spot with a diameter of approximately 5 mm was nondestructively read out by the technique. The spot size was smaller than the wavelengths used for the read out, indicating the advantage of using the near-field technique.

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Selective Recognition of Endocrine Disruptors by Fluorogenic γ-Cyclodextrin Having Pyrene-Tosyl Substituents on Hetero Rims

Abstract: Cyclodextrins (CyDs) have attracted interest as an enzyme model or supramolecular compounds, because they can accommodate with a variety of guests, such as organic molecules or metals, in their cavities in an aqueous solution.

Cited by 13 publications

References 26 publications

Calcite Formation in Soft Coral Sclerites Is Determined by a Single Reactive Extracellular Protein

Calcite Formation in Soft Coral Sclerites Is Determined by a Single Reactive Extracellular Protein

Analysis of Protein-induced Calcium Carbonate Crystals in Soft Coral by Near-Field IR Microspectroscopy

Micrometer-Scale Photochromic Recording on Amorphous Diarylethene Film and Nondestructive Readout Using Near-Field IR Light

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