Interaction of a C-terminal peptide of Bos taurus diacylglycerol acyltransferase 1 with model membranes

Talhari, Daniella T.; Moraes, Marli L.; Castilho, Priscila V.; Oliveira, Osvaldo N.; Beltramini, Leila Maria; Araújo, Ana Paula Ulian de

doi:10.1016/j.bbamem.2009.07.023

Cited by 7 publications

(4 citation statements)

References 26 publications

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“…29 The spectrum in methanol exhibited a blue shift to 340 nm for the tryptophan emission, indicating an organized structure. 29 30 Normally, the interaction between a chromophore and liposomes causes a blue shift and quenching in the spectrum, 31 which indeed occurred for the peptide incorporated in the liposomes. The maximum appeared at 343 nm, similarly to p17-1 in methanol, from which one infers that the peptides are structured in the liposomes.…”

Section: Resultsmentioning

confidence: 98%

Toward Preserving the Structure of the Antigenic Peptide p17-1 from the HIV-1 p17 Protein in Nanostructured Films

Petri

Ferreira²,

Moraes³

2011

J. Nanosci. Nanotech.

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Antigenic peptides may be immobilized in nanostructured films in order to build highly specific immunosensors and other devices that require molecular recognition, with no need to use complex molecules. A major challenge for such endeavors, however, is to preserve the secondary structure of the peptides after immobilization. In this study, we show that the peptide p17-1 (LSGGELDRWEKIRLRPGG), derived from the HIV-1 p17 protein, may be immobilized in Layer-by-Layer (LbL) films made with polyelectrolytes. Its structure was preserved only if incorporated into phospholipid liposomes, according to fluorescence and circular dichroism (CD) spectroscopy. The lack of secondary structure for the peptide in the LbL film may be associated with the film-forming procedure in which p17-1 was adsorbed from an aqueous solution, where it does not form alpha helices. The importance of structure preservation was clear in the attempts to produce electrochemical immunosensors with the p17-1 peptide without being protected in liposomes in an LbL film. There was no detectable influence of the presence of anti-p17 antibodies, though some molecular interaction could be inferred from the voltammograms. In contrast, for p17-1 incorporated in liposomes electrochemical immunosensors could be obtained with the voltamogramms showing strong molecular recognition with the antibodies. These results indicated that phospholipids serve as a suitable matrix for immobilization of peptides, and confirmed the importance of structure preservation in electrochemical immunosensors.

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Section: Resultsmentioning

confidence: 98%

Toward Preserving the Structure of the Antigenic Peptide p17-1 from the HIV-1 p17 Protein in Nanostructured Films

Petri

Ferreira²,

Moraes³

2011

J. Nanosci. Nanotech.

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“…Meanwhile, other studies with DGAT1 from mice suggested that the N-terminal segment is able to specifically bind to different acyl-CoAs [15]. Bovine DGAT1 shares a conserved region with the ACAT enzymes [16], which also suggests a potential binding region for this substrate. Both these binding sites are proposed to lie within an extramembranous loop of the protein.…”

Section: Introductionmentioning

confidence: 99%

Deconstructing the DGAT1 Enzyme: Membrane Interactions at Substrate Binding Sites

Lopes¹,

Beltramini²,

Wallace

et al. 2015

PLoS ONE

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Diacylglycerol acyltransferase 1 (DGAT1) is a key enzyme in the triacylglyceride synthesis pathway. Bovine DGAT1 is an endoplasmic reticulum membrane-bound protein associated with the regulation of fat content in milk and meat. The aim of this study was to evaluate the interaction of DGAT1 peptides corresponding to putative substrate binding sites with different types of model membranes. Whilst these peptides are predicted to be located in an extramembranous loop of the membrane-bound protein, their hydrophobic substrates are membrane-bound molecules. In this study, peptides corresponding to the binding sites of the two substrates involved in the reaction were examined in the presence of model membranes in order to probe potential interactions between them that might influence the subsequent binding of the substrates. Whilst the conformation of one of the peptides changed upon binding several types of micelles regardless of their surface charge, suggesting binding to hydrophobic domains, the other peptide bound strongly to negatively-charged model membranes. This binding was accompanied by a change in conformation, and produced leakage of the liposome-entrapped dye calcein. The different hydrophobic and electrostatic interactions observed suggest the peptides may be involved in the interactions of the enzyme with membrane surfaces, facilitating access of the catalytic histidine to the triacylglycerol substrates.

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“…involving changes in peptide conformation (B). Reproduced with permission from reference [37]. A C C E P T E D M A N U S C R I P T…”

Section: Accepted Manuscriptmentioning

confidence: 98%

“…Therefore, in order to determine DGAT1 regions involved in substrate binding, specific regions of the protein were synthesized. Talhari and coworkers studied the peptide NIPVHKWAIR HFYKP, referred to as SIT2, on the C-terminal of DGAT1 [37]. The choice of this region was due to the presence of a putative diacylglycerol binding domain.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Interactions of bioactive molecules & nanomaterials with Langmuir monolayers as cell membrane models

et al. 2015

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Interaction of a C-terminal peptide of Bos taurus diacylglycerol acyltransferase 1 with model membranes

Cited by 7 publications

References 26 publications

Toward Preserving the Structure of the Antigenic Peptide p17-1 from the HIV-1 p17 Protein in Nanostructured Films

Toward Preserving the Structure of the Antigenic Peptide p17-1 from the HIV-1 p17 Protein in Nanostructured Films

Deconstructing the DGAT1 Enzyme: Membrane Interactions at Substrate Binding Sites

Interactions of bioactive molecules & nanomaterials with Langmuir monolayers as cell membrane models

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