Circular Dichroism

Publication Title: 
Journal of Natural Products

The endophytic fungus Pestalotiopsis virgatula, derived from the plant Terminalia chebula and previously found to produce a large excess of a single metabolite when grown in the minimal M1D medium, was induced to produce a variety of unusual metabolites by growing in potato dextrose broth medium. Analysis of the fermentation medium extract was performed using an HPLC-PDA-MS-SPE-NMR hyphenated system, which led to the identification of a total of eight metabolites (1-8), six of which are new.

Author(s): 
Kesting, Julie R.
Olsen, Lars
Staerk, Dan
Tejesvi, Mysore V.
Kini, Kukkundoor R.
Prakash, Harishchandra S.
Jaroszewski, Jerzy W.
Publication Title: 
Proceedings of the National Academy of Sciences of the United States of America

Forkhead box class O 3a (FOXO3a) is a transcription factor and tumor suppressor linked to longevity that determines cell fate through activating transcription of cell differentiation, survival, and apoptotic genes. Recruitment of the coactivator CBP/p300 is a crucial step in transcription, and we revealed that in addition to conserved region 3 (CR3) of FOXO3a, the C-terminal segment of CR2 (CR2C) binds CBP/p300 and contributes to transcriptional activity.

Author(s): 
Wang, Feng
Marshall, Christopher B.
Yamamoto, Kazuo
Li, Guang-Yao
Gasmi-Seabrook, GeneviËve M. C.
Okada, Hitoshi
Mak, Tak W.
Ikura, Mitsuhiko
Publication Title: 
Nucleic Acids Research

We examined structural properties of poly d(C4A2).d(T2G4), the telomeric DNA sequence of the ciliated protozoan Tetrahymena. Under conditions of high negative supercoiling, poly d(C4A2).d(T2G4) inserted in a circular plasmid vector was preferentially sensitive to digestion with S1 nuclease. Only the C4A2 strand was sensitive to first-strand S1 cutting, with a markedly skewed pattern of hypersensitive sites in tracts of either 46 or 7 tandem repeats.

Author(s): 
Budarf, M.
Blackburn, E.
Publication Title: 
Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy

R-(+)-Pulegone is a natural monoterpene obtained from the essential oils of a variety of plants. It is used in flavouring agents, perfumery and aromatherapy. In this work, a study of the molecular structure and the infrared and Raman spectra of this chemical is presented. Theoretical calculations reveal the existence of two conformers depending on the position of the methyl group (axial and equatorial), being the equatorial conformer the most stable.

Author(s): 
Aviles-Moreno, Juan Ram�n
Ure�a Horno, Elena
Partal Ure�a, Francisco
L�pez Gonz�lez, Juan Jes�s
Publication Title: 
Biochemical and Biophysical Research Communications

We have identified oleuropein (Ole) and hydroxytyrosol (HT) as a unique class of HIV-1 inhibitors from olive leaf extracts effective against viral fusion and integration. We used molecular docking simulation to study the interactions of Ole and HT with viral targets. We find that Ole and HT bind to the conserved hydrophobic pocket on the surface of the HIV-gp41 fusion domain by hydrogen bonds with Q577 and hydrophobic interactions with I573, G572, and L568 on the gp41 N-terminal heptad repeat peptide N36, interfering with formation of the gp41 fusion-active core.

Author(s): 
Lee-Huang, Sylvia
Huang, Philip Lin
Zhang, Dawei
Lee, Jae Wook
Bao, Ju
Sun, Yongtao
Chang, Young-Tae
Zhang, John
Huang, Paul Lee
Publication Title: 
Molecular Vision

PURPOSE: To determine comparative effects of ultraviolet (UV)-A irradiation on structural and functional properties of wild type (WT) alphaB-crystallin and its three deamidated mutant proteins (alphaB-Asn78Asp, alphaB-Asn146Asp, and alphaB-Asn78/146Asp). METHODS: Three deamidated mutants previously generated from recombinant WT alphaB-crystallin, using a site-specific mutagenesis procedure as previously described [32], were used. The WT alphaB-crystallin and its three deamidated species were exposed to UV-A light (320-400 nm) at intensities of 20 or 50 J/cm(2).

Author(s): 
Mafia, Kerri
Gupta, Ratna
Kirk, Marion
Wilson, L.
Srivastava, O. P.
Barnes, Stephen
Publication Title: 
Biochemistry

The purpose of the study was to determine the effects of truncation of various regions of betaB1-crystallin on its structural properties and stability of heterooligomers formed by wild-type (WT) betaB1 or its deletion mutants with WT betaA3-crystallin.

Author(s): 
Srivastava, K.
Gupta, R.
Chaves, J. M.
Srivastava, O. P.
Publication Title: 
Journal of Molecular Biology

Current drugs used for antiretroviral therapy against human immunodeficiency virus (HIV) have a narrow spectrum of activity and, more often, have associated toxicities and severe side effects in addition to developing resistance. Thus, there is a need to develop new therapeutic strategies against HIV/AIDS to complement the already existing ones. Surprisingly, transactivator of transcription (Tat), an early virus-encoded protein required for the efficient transcription of the HIV genome, has not been developed as a target for small molecular therapeutics.

Author(s): 
Narayan, Vivek
Ravindra, Kodihalli C.
Chiaro, Chris
Cary, Daniele
Aggarwal, Bharat B.
Henderson, Andrew J.
Prabhu, K. Sandeep
Publication Title: 
Journal of Natural Products

Isosilybin A (1) is one of the major flavonolignans that constitute silymarin, an extract of the fruits (achenes) of milk thistle (Silybum marianum). The chemistry of the Silybum flavonolignans has been studied for over four decades, and the absolute configuration of 1 has been determined previously by electronic circular dichroism and X-ray crystallography via correlating the relative configuration of the phenylpropanoid moiety to the established absolute configuration of the 3-hydroxyflavanone portion of the molecule.

Author(s): 
Sy-Cordero, Arlene A.
Day, Cynthia S.
Oberlies, Nicholas H.
Publication Title: 
Organic Letters

A new pyrroloiminoquinone alkaloid, named atkamine, with an unusual scaffold was discovered from a cold, deep water Alaskan sponge Latrunculia sp. collected from the Aleutian Islands. Olefin metathesis was utilized to determine the location of the double bond in the hydrocarbon chain. The absolute configuration was determined by using computational approaches combing with the ECD (electronic circular dichroism) spectroscopy.

Author(s): 
Zou, Yike
Hamann, Mark T.

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