γ‐Zein secondary structure in solution by circular dichroism

Bicudo, Tatiana C.; Bicudo, Rogério Campos; Forato, L. A.; Beltramini, Leila Maria; Batista, L. A. R.; Filho, Rubens Bernardes; Colnago, Luiz Alberto

doi:10.1002/bip.20884

Cited by 15 publications

(23 citation statements)

References 23 publications

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“…Analysis of the secondary structure of the entire ␥-zein protein by CD spectra in aqueous media showed that the whole protein has a high helical content but a low PPII conformation content, at 55 and 7%, respectively (57). In contrast, the synthetic peptide (PPPVHL) 8 , corresponding to the repeat region, has been shown to adopt an amphipathic polyproline II conformation (27,44) and has been linked to a new family of cell-penetrating peptides (58).…”

Section: Discussionmentioning

confidence: 99%

Relevant Elements of a Maize γ-Zein Domain Involved in Protein Body Biogenesis

Llop‐Tous

Madurga

Giralt

et al. 2010

Journal of Biological Chemistry

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The N-terminal proline-rich domain of ␥-zein (Zera) plays an important role in protein body (PB) formation not only in the original host (maize seeds) but in a broad spectrum of eukaryotic cells. However, the elements within the Zera sequence that are involved in the biogenesis of PBs have not been clearly identified. Here, we focused on amino acid sequence motifs that could be involved in Zera oligomerization, leading to PB-like structures in Nicotiana benthamiana leaves. By using fusions of Zera with fluorescent proteins, we found that the lack of the repeat region (PPPVHL) 8 of Zera resulted in the secretion of the fusion protein but that this repeat by itself did not form PBs. Although the repeat region containing eight units was the most efficient for Zera self-assembly, shorter repeats of 4 -6 units still formed small multimers. Based on site-directed mutagenesis of Zera cysteine residues and analysis of multimer formation, we conclude that the two N-terminal Cys residues of Zera (Cys 7 and Cys 9 ) are critical for oligomerization. Immunoelectron microscopy and confocal studies on PB development over time revealed that early, small, Zera-derived oligomers were sequestered in buds along the rough ER and that the mature size of the PBs could be attained by both cross-linking of preformed multimers and the incorporation of new chains of Zera fusions synthesized by active membrane-bound ribosomes. Based on these results and on the behavior of the Zera structure determined by molecular dynamics simulation studies, we propose a model of Zera-induced PB biogenesis.The mechanisms by which prolamins, which lack the ER 3 retention (H/K)DEL motif, are retained and assembled in the ER-derived PBs are only partially understood. Different factors act as determinants of PB biogenesis, some of them derived from cis-cargo properties and others with a cellular trans-origin (1). It has been proposed that the physico-chemical properties of prolamins, such as hydrophobicity and disulfide bond formation, promote specific interactions resulting in the formation of large self-assemblies that are responsible for their retention in the ER and PB formation (2-4). These polymers could be excluded because of their size from being carried by the COP II vesicles that transport cargo proteins to the Golgi complex (5). However, the generic COPII vesicles are flexible enough for large cargo loading, including that of procollagen (more than 300 nm in size) (6) and the collagen VII trimer (900 kDa) (7).In maize, four distinct types of prolamins (␣-, ␤-, ␥-, and ␦-zein) coexist in the PBs (8) and play distinct roles in PB formation. Recently, maize storage protein mutants created through RNAi showed that ␥-RNAi maize mutant lines exhibited slightly altered protein body formation and that a more drastic effect was observed in the ␤-␥ combined mutant, where protein bodies showed an irregular shape, particularly in their periphery (9).Various studies on zein accumulation in heterologous expression systems suggest that ␥-zein and ␤-zein mediate t...

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Section: Discussionmentioning

confidence: 99%

Relevant Elements of a Maize γ-Zein Domain Involved in Protein Body Biogenesis

Llop‐Tous

Madurga

Giralt

et al. 2010

Journal of Biological Chemistry

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“…20,21 Owing to its semiextended nature, the P II protein domains are predictably highly solvent exposed in aqueous media. 22 Although amphipathic P II -forming sequences do appear in nature, 23,24 there is no evidence for the existence of a natural P II helix that would be purely hydrophobic.…”

Section: Hydrophobic Peptidesmentioning

confidence: 99%

Exploring hydrophobicity limits of polyproline helix with oligomeric octahydroindole‐2‐carboxylic acid

Kubyshkin

Budiša

2018

Journal of Peptide Science

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The polyproline-II helix is the most extended naturally occurring helical structure and is widely present in polar, exposed stretches and "unstructured" denatured regions of polypeptides. Can it be hydrophobic? In this study, we address this question using oligomeric peptides formed by a hydrophobic proline analogue, (2S,3aS,7aS)-octahydroindole-2-carboxylic acid (Oic). Previously, we found the molecular principles underlying the structural stability of the polyproline-II conformation in these oligomers, whereas the hydrophobicity of the peptide constructs remains to be examined. Therefore, we investigated the octan-1-ol/water partitioning and inclusion in detergent micelles of the oligo-Oic peptides. The results showed that the hydrophobicity is remarkably enhanced in longer oligomeric sequences, and the oligo-Oic peptides with 3 to 4 residues and higher are specific towards hydrophobic environments. This contrasts significantly to the parent oligoproline peptides, which were moderately hydrophilic. With these findings, we have demonstrated that the polyproline-II structure is compatible with nonpolar media, whereas additional manipulations of the terminal functionalities feature solubility in extremely nonpolar solvents such as hexane.

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“…Zein is the major storage protein of corn and an important source of protein in the human diet either through direct consumption or through consumption of animals whose feed is based on corn, such as poultry or swines [13]. Although zein is known since 1821 [14–15], there is only recent interest in this protein focusing on its potential technological use [16–17].…”

Section: Introductionmentioning

confidence: 99%

Effective intercalation of zein into Na-montmorillonite: role of the protein components and use of the developed biointerfaces

Alcántara¹,

Darder²,

Ruiz‐Hitzky³

2016

Beilstein J. Nanotechnol.

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Biohybrid materials based on the intercalation of zein, the major storage protein in corn, into sodium-exchanged montmorillonite were prepared following two synthesis strategies. The first one made use of zein dissolved in 80% (v/v) ethanol/water solution, the usual solvent for this protein, while the second method is new and uses a sequential process that implies the previous separation of zein components in absolute ethanol. This treatment of zein with ethanol renders a soluble yellow phase and an agglomerate of insoluble components, which are able to intercalate the layered silicate when an aqueous dispersion of montmorillonite is added to the ethanol medium containing both phases. The diverse steps in this second route were investigated individually in order to understand the underlying mechanism that drives to the intercalation of this complex hydrophobic biomacromolecule into the hydrophilic interlayer space of sodium-exchanged montmorillonite. In addition to physicochemical characterization of the resulting materials, these biohybrid interfaces were also evaluated as biofillers in the preparation of diverse ecofriendly nanocomposites.

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γ‐Zein secondary structure in solution by circular dichroism

Cited by 15 publications

References 23 publications

Relevant Elements of a Maize γ-Zein Domain Involved in Protein Body Biogenesis

Relevant Elements of a Maize γ-Zein Domain Involved in Protein Body Biogenesis

Exploring hydrophobicity limits of polyproline helix with oligomeric octahydroindole‐2‐carboxylic acid

Effective intercalation of zein into Na-montmorillonite: role of the protein components and use of the developed biointerfaces

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