Publications (8)18.79 Total impact
-
Article: Theoretical Structural Insights into the Snakin/GASA Family.
[show abstract] [hide abstract]
ABSTRACT: Among the main classes of cysteine-stabilized antimicrobial peptides, the snakin/GASA family has not yet had any structural characterization. Through the combination of ab initio and comparative modeling with a disulfide bond predictor, the three-dimensional structure prediction of snakin-1 is here reported. The structure was composed of two long α-helices with a disulfide pattern of Cys(I)-Cys(IX), Cys(II)-Cys(VII), Cys(III)-Cys(IV), Cys(V)-Cys(XI), Cys(VI)-Cys(XII) and Cys(VIII)-Cys(X). The overall structure was maintained throughout molecular dynamics simulation. Snakin-1 showed a small degree of structural similarity with thionins and α-helical hairpins. This is the first report of snakin-1 structural characterization, shedding some light on the snakin/GASA family.Peptides 04/2013; · 2.43 Impact Factor -
Article: In silico identification of novel hevein-like peptide precursors.
[show abstract] [hide abstract]
ABSTRACT: Lectins are proteins with ability to bind reversibly and non-enzymatically to a specific carbohydrate. They are involved in numerous biological processes and show enormous biotechnological potential. Among plant lectins, the hevein domain is extremely common, being observed in several kinds of lectins. Moreover, this domain is also observed in an important class of antimicrobial peptides named hevein-like peptides. Due to higher cysteine residues conservation, hevein-like peptides could be mined among the sequence databases. By using the pattern CX(4,5)CC[GS]X(2)GXCGX[GST]X(2,3)[FWY]C[GS]X[AGS] novel hevein-like peptide precursors were found from three different plants: Oryza sativa, Vitis vinifera and Selaginella moellendorffii. In addition, an hevein-like peptide precursor from the phytopathogenic fungus Phaeosphaeria nodorum was also identified. The molecular models indicate that they have the same scaffold as others, composed of an antiparallel β-sheet and short helices. Nonetheless, the fungal hevein-like peptide probably has a different disulfide bond pattern. Despite this difference, the complexes between peptide and N,N,N-triacetylglucosamine are stable, according to molecular dynamics simulations. This is the first report of an hevein-like peptide from an organism outside the plant kingdom. The exact role of an hevein-like peptide in the fungal biology must be clarified, while in plants they are clearly involved in plant defense. In summary, data here reported clear shows that an in silico strategy could lead to the identification of novel hevein-like peptides that could be used as biotechnological tools in the fields of health and agribusiness.Peptides 09/2012; 38(1):127-136. · 2.43 Impact Factor -
Chapter: Prediction and Rational Design of Antimicrobial Peptides
04/2012; , ISBN: 978-953-51-0555-8 -
Chapter: Prediction and Rational Design of Antimicrobial Peptides
[show abstract] [hide abstract]
ABSTRACT: In recent decades the activity of conventional antibiotics against pathogenic bacteria has decreased due to the development of resistance. This phenomenon has generated the socalled ‘superbugs’, which are multi-resistant bacteria. In this context, antimicrobial peptides (AMP) appear as an alternative to control them. AMPs have been found in several sources, including animals, plants and fungi, constituting the first line of host defence against pathogens. However, the use of AMPs as therapeutic agents has some limitations, such as stability, cytotoxicity and mainly their amino acid length, since amino acids are expensive building blocks. Despite these limitations they have compensatory properties, including secondary activities such as immunomodulation or antitumor ones. Several methods have been applied since the 1990s for rational AMPs design, in order to generate analogues with improved activity, looking to reduce limitations and increase advantages. Computer-aided identification and design of AMPs play a crucial role in this area. The discovery of AMP properties, through the first rational design studies, will allow the development of methods for prediction of AMPs, which in turn, should lead to identification prior to synthesis of novel analogues. Thus, this chapter will be dedicated to describing important techniques in prediction and rational design of AMPs and their applications for drug development.04/2012: pages 20; , ISBN: William F. Porto, Osmar N. Silva and Octávio L. Franco (2012). Prediction and Rational Design of Antimicrobial Peptides, Protein Structure, Dr. Eshel Faraggi (Ed.), ISBN: 978-953-51-0555-8, InTech, Available from: http://www.intechopen.com/books/protein-s -
Article: CnAMP-1: A new promiscuous peptide with potential for microbial infections treatment
[show abstract] [hide abstract]
ABSTRACT: The antimicrobial peptides (AMPs) are evolutionarily ancient molecules that act as components of the innate immune system. Recently, it was demonstrated that a single antimicrobial peptide can perform various functions; this ability is known as ‘peptide promiscuity’. However, little is known about promiscuity in plant antimicrobial peptides without disulphide bonds. This study was carried out in order to evaluate the promiscuity of Cn-AMP1: a promising disulphide-free plant peptide with reduced size and cationic and hydrophobic properties. Its activity against human pathogenic bacteria and fungal pathogens, as well as their in vitro immuno-stimulatory activity and effects on cancerous and healthy mammalian cell proliferation were studied here. Cn-AMP1 exerts antimicrobial effects against Gram-positive bacteria, Gram-negative bacteria and fungi. Moreover, reduced tumour cell viability (Caco-2), as well as immuno-stimulatory activity by evaluating up-regulated inflammatory-cytokine secretion by monocytes was also positively observed. Cn-AMP1 does not exhibit a well-defined conformation in aqueous solution and probably undergoing a 310-helix transition in hydrophobic environments. The experimental results support the promiscuous activity of Cn-AMP1, presenting a wide range of activities, including antibacterial, antifungal and immuno-stimulatory activity. In the future, Cn-AMP1, should be used in the development of novel biopharmaceuticals, mainly due to its reduced size and broad spectrum of activity.Biopolymers 04/2012; 98(2). · 2.87 Impact Factor -
Article: Cn-AMP1: a new promiscuous peptide with potential for microbial infections treatment.
[show abstract] [hide abstract]
ABSTRACT: The antimicrobial peptides (AMPs) are evolutionarily ancient molecules that act as components of the innate immune system. Recently, it was demonstrated that a single AMP can perform various functions; this ability is known as "peptide promiscuity." However, little is known about promiscuity in plant AMPs without disulfide bonds. This study was carried out to evaluate the promiscuity of Cn-AMP1: a promising disulfide-free plant peptide with reduced size and cationic and hydrophobic properties. Its activity against human pathogenic bacteria and fungal pathogens, as well as its in vitro immunostimulatory activity and effects on cancerous and healthy mammalian cell proliferation were studied here. Cn-AMP1 exerts antimicrobial effects against Gram-positive bacteria, Gram-negative bacteria, and fungi. Moreover, tumor cell viability activity in Caco-2 cells, as well as immunostimulatory activity by evaluating upregulated inflammatory-cytokine secretion by monocytes was also positively observed. Cn-AMP1 does not exhibit a well-defined conformation in aqueous solution and probably undergoes a 3(10)-helix transition in hydrophobic environments. The experimental results support the promiscuous activity of Cn-AMP1, presenting a wide range of activities, including antibacterial, antifungal, and immunostimulatory activity. In the future, Cn-AMP1 should be used in the development of novel biopharmaceuticals, mainly due to its reduced size and broad spectrum of activity.Biopolymers 01/2012; 98(4):322-31. · 2.87 Impact Factor -
Article: CS-AMPPred: An Updated SVM Model for Antimicrobial Activity Prediction in Cysteine-Stabilized Peptides.
[show abstract] [hide abstract]
ABSTRACT: The antimicrobial peptides (AMP) have been proposed as an alternative to control resistant pathogens. However, due to multifunctional properties of several AMP classes, until now there has been no way to perform efficient AMP identification, except through in vitro and in vivo tests. Nevertheless, an indication of activity can be provided by prediction methods. In order to contribute to the AMP prediction field, the CS-AMPPred (Cysteine-Stabilized Antimicrobial Peptides Predictor) is presented here, consisting of an updated version of the Support Vector Machine (SVM) model for antimicrobial activity prediction in cysteine-stabilized peptides. The CS-AMPPred is based on five sequence descriptors: indexes of (i) α-helix and (ii) loop formation; and averages of (iii) net charge, (iv) hydrophobicity and (v) flexibility. CS-AMPPred was based on 310 cysteine-stabilized AMPs and 310 sequences extracted from PDB. The polynomial kernel achieves the best accuracy on 5-fold cross validation (85.81%), while the radial and linear kernels achieve 84.19%. Testing in a blind data set, the polynomial and radial kernels achieve an accuracy of 90.00%, while the linear model achieves 89.33%. The three models reach higher accuracies than previously described methods. A standalone version of CS-AMPPred is available for download at <http://sourceforge.net/projects/csamppred/> and runs on any Linux machine.PLoS ONE 01/2012; 7(12):e51444. · 4.09 Impact Factor -
Article: Evaluation of an antimicrobial L-amino acid oxidase and peptide derivatives from Bothropoides mattogrosensis pitviper venom.
[show abstract] [hide abstract]
ABSTRACT: Healthcare-associated infections (HAIs) are causes of mortality and morbidity worldwide. The prevalence of bacterial resistance to common antibiotics has increased in recent years, highlighting the need to develop novel alternatives for controlling these pathogens. Pitviper venoms are composed of a multifaceted mixture of peptides, proteins and inorganic components. L-amino oxidase (LAO) is a multifunctional enzyme that is able to develop different activities including antibacterial activity. In this study a novel LAO from Bothrops mattogrosensis (BmLAO) was isolated and biochemically characterized. Partial enzyme sequence showed full identity to Bothrops pauloensis LAO. Moreover, LAO here isolated showed remarkable antibacterial activity against Gram-positive and -negative bacteria, clearly suggesting a secondary protective function. Otherwise, no cytotoxic activities against macrophages and erythrocytes were observed. Finally, some LAO fragments (BmLAO-f1, BmLAO-f2 and BmLAO-f3) were synthesized and further evaluated, also showing enhanced antimicrobial activity. Peptide fragments, which are the key residues involved in antimicrobial activity, were also structurally studied by using theoretical models. The fragments reported here may be promising candidates in the rational design of new antibiotics that could be used to control resistant microorganisms.PLoS ONE 01/2012; 7(3):e33639. · 4.09 Impact Factor
Top co-authors
Top Journals
- Biopolymers (2)
- Peptides (2)
- PLoS ONE (2)
Institutions
-
2012
-
Universidade Católica de Brasília
- Centro de Análises Proteômicas e Bioquímicas - CAPB
Brasília, Distrito Federal, Brazil
-
