Stabilities for the eight isomeric forms of the steroid skeleton (perhydrocyclopentanophenanthrene)

Tantuco, Kathleen; Deretey, Eugen; Csizmadia, Imre G.

doi:10.1016/s0166-1280(99)00366-8

Cited by 8 publications

(4 citation statements)

References 8 publications

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“…The structural difference between cholesterol and the 7-dehydrocholesterol is the formation of a double-bond in the steroid ring between carbon 7 and 8. It is possible that 7-dehydrocholesterol may adapt to a different conformation from that of cholesterol regarding the trans/cis status of the sterol ring (42), therefore binding of 7-dehydrocholesterol may require a slightly different cavity space that Y30 in AeSCP-2 could not provide. It is noticed that amino acid residues at the equivalent positions in AeSCP-2-like proteins are not conserved in all members of the family (1), suggesting that other members of the AeSCP-2 like proteins in the protein family may bind to 7-dehydrocholesterol.…”

Section: Discussionmentioning

confidence: 99%

Effects of Mutations in Aedes aegypti Sterol Carrier Protein-2 on the Biological Function of the Protein

2010

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Sterol carrier protein-2 (SCP-2) is a non-specific intracellular lipid carrier protein. However, the molecular mechanism of ligand selectivity and the in vivo function of SCP-2 remain unclear. In this study, we used site directed mutagenesis to investigate ligand selectivity and in vivo function of the yellow fever mosquito sterol carrier protein-2 protein (AeSCP-2). Mutations to amino acids in AeSCP-2 known to interact with bound ligand also decreased NBD-cholesterol binding. Substitution of amino acids in the ligand cavity changed the ligand specificity of mutant AeSCP-2. Over-expressing AeSCP-2 wild-type in the Aedes aegypti cultured Aag-2 cells resulted in an increase in incorporation of [3H]cholesterol. However, over-expressing mutants that were deleterious to the binding of NBD-cholesterol in AeSCP-2 showed a loss in the ability to enhance uptake of [3H] cholesterol in cultured cells. Interestingly, when [3H]palmitic acid was used as the substrate for incorporation in vivo, there was no change in the levels of incorporation with over-expression of wild-type protein or mutated AeSCP-2s. The in vivo data suggest that AeSCP-2 is involved in sterol uptake, but not fatty acid uptake. This is the first report that the ability of cholesterol binding may directly correlate to AeSCP-2’s in vivo function in aiding the uptake of cholesterol.

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Section: Discussionmentioning

confidence: 99%

Effects of Mutations in Aedes aegypti Sterol Carrier Protein-2 on the Biological Function of the Protein

2010

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“…We can clearly exclude candidate (4), namely breaking down of the steroidal structure. Due to the 'trans' configuration at all three fusions, the steroidal structure is commonly rigid and remains semi-flat [30]. That is why cholesterol, the most abundant steroid in animals, is so stable in animal's body [31].…”

Section: Discussionmentioning

confidence: 99%

Detection of Surface Modification of Polyimide Containing Steroidal Structure as a Function of Storage Time Using Second-Order Nonlinear Optical Spectroscopy

Nguyen,

Du,

Khuat

et al. 2023

e-J. Surf. Sci. Nanotechnol.

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The modification of a polyimide surface containing a 30% fraction of steroidal structure was studied as a function of storage time by vibrational sum frequency generation (SFG) spectroscopy and optical second-harmonic generation (SHG). The variation of the symmetric and anti-symmetric stretching modes of the CH 3 isopropyl group at the end of the side chain of the rubbed polyimide was detected in the SFG spectra after a 3-month storage time in a practical environment. It suggests that the isopropyl group might be reoriented. On the other hand, the SHG response of the same sample showed an insignificant storage-time dependence. As a result, the phenyl rings of the polyimide are judged to be unmodified after long-term storage time. The change is suggested to occur for two main reasons. One is the interaction between the polyimide polymers and the ambient water molecules. The other is the adsorption of unknown organic molecules on the polyimide surface.

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“…We can clearly exclude candidate (4), namely breaking down of the steroidal structure. Due to the 'trans' con guration at all three fusions, the steroidal structure is commonly rigid and remains semi-at [30].…”

Section: Discussionmentioning

confidence: 99%

Detection of surface modification of polyimide containing steroidal structure as a function of storage time using second- order nonlinear optical spectroscopy

Nguyen

Khuat

et al. 2022

Preprint

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The modification of a polyimide surface containing a 30% fraction of steroidal structure was studied as a function of storage time by vibrational sum frequency generation (SFG) spectroscopy and optical second-harmonic generation (SHG). The variation of the symmetric and anti-symmetric stretching modes of the CH3 isopropyl group at the end of the side chain of the rubbed polyimide was detected in the SFG spectra after 3 months storage time in a practical environment. It suggests that the isopropyl group might be reoriented. On the other hand, the SHG response of the same sample showed an insignificant storage-time dependence. As a result, the phenyl rings of the polyimide are judged to be unmodified after long-term storage time. The change is suggested to occur for two main reasons. One is the interaction between the polyimide polymers and the ambient water molecules. The other is the adsorption of unknown organic molecules on the polyimide surface.

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Stabilities for the eight isomeric forms of the steroid skeleton (perhydrocyclopentanophenanthrene)

Cited by 8 publications

References 8 publications

Effects of Mutations in Aedes aegypti Sterol Carrier Protein-2 on the Biological Function of the Protein

Effects of Mutations in Aedes aegypti Sterol Carrier Protein-2 on the Biological Function of the Protein

Detection of Surface Modification of Polyimide Containing Steroidal Structure as a Function of Storage Time Using Second-Order Nonlinear Optical Spectroscopy

Detection of surface modification of polyimide containing steroidal structure as a function of storage time using second- order nonlinear optical spectroscopy

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