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Open AccessArticle

Heavy Metal Complexation of Thiol-Containing Peptides from Soy Glycinin Hydrolysates

by Xiuzhen Ding, Yufei Hua, Yeming Chen, Caimeng Zhang and Xiangzhen Kong

Int. J. Mol. Sci. 2015, 16(4), 8040-8058; https://doi.org/10.3390/ijms16048040 - 10 Apr 2015

Cited by 27 | Viewed by 6381

Abstract

Many thiol-containing molecules show heavy metal complexation ability and are used as antidotes. In this study, the potential function associated with thiol-containing peptides (TCPs) from soy protein hydrolysates as natural detoxicants for heavy metals is reported. TCPs enriched by Thiopropyl-Sepharose 6B covalent chromatography [...] Read more.

Many thiol-containing molecules show heavy metal complexation ability and are used as antidotes. In this study, the potential function associated with thiol-containing peptides (TCPs) from soy protein hydrolysates as natural detoxicants for heavy metals is reported. TCPs enriched by Thiopropyl-Sepharose 6B covalent chromatography had different molecular weight distributions as well as different numbers of proton dissociable groups, depending on the proteases and degree of hydrolysis. The major contribution of sulfhydryl groups was confirmed by the largest pH decrease between 8.0 and 8.5 of the pH titration curves. The complexation of TCPs with heavy metalswas evaluated by stability constants (β_n) of TCP-metal complexes whose stoichiometry was found to be 1:1 (ML) and 1:2 (ML₂). TCPs from degree of hydrolysis of 25% hydrolysates gave high affinities towards Hg²⁺, Cd²⁺, and Pb²⁺ (giving similar or even bigger lgβ values than that of glutathione). A significantly positive correlation was found between the logarithm of stability constants for ML₂ (lgβ₂) and the sulfhydryl group content. Molecular weight distribution of TCPs affected the complexation with Pb²⁺ notably more than Hg²⁺ and Cd²⁺. These results suggest that soy TCPs have the potential to be used in the formulation of functional foods to counteract heavy metal accumulation in humans. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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708 KiB

Open AccessArticle

Characterization and Antihyperglycemic Activity of a Polysaccharide from Dioscorea opposita Thunb Roots

by Yijun Fan, Qinyi He, Aoshuang Luo, Miaoyu Wang and Aoxue Luo

Int. J. Mol. Sci. 2015, 16(3), 6391-6401; https://doi.org/10.3390/ijms16036391 - 19 Mar 2015

Cited by 56 | Viewed by 7164

Abstract

A polysaccharide DOTP-80 from Dioscorea opposita Thunb was obtained by using the method of acid water-extraction and ethanol-precipitation. After being purified by chromatography, the structure characteristics of DOTP-80 were established. Based on the calibration curve obtained with standard dextrans, the molecular weight of [...] Read more.

A polysaccharide DOTP-80 from Dioscorea opposita Thunb was obtained by using the method of acid water-extraction and ethanol-precipitation. After being purified by chromatography, the structure characteristics of DOTP-80 were established. Based on the calibration curve obtained with standard dextrans, the molecular weight of the polysaccharide fraction DOTP-80 was calculated to be 123 kDa. The results of Infrared spectrum (FT-IR) indicated that the polysaccharide contained the α-configuration of sugar units. GC-MS analysis revealed that DOTP-80 was mainly composed of mannose and glucose. Alloxan-induced diabetic rats and mice models were developed to evaluate the in vivo hypoglycemic activity of the polysaccharide. The results indicated that a high dose DOTP-80 (400 mg/kg) had strong hypoglycemic activity. Moreover, DOTP-80 could increase the level of antioxidant enzymes (SOD) activity in alloxan-induced diabetic mice and stimulate an increase in glucose disposal in diabetic rats. Therefore, the polysaccharide DOTP-80 should be evaluated as a candidate for future studies on diabetes mellitus. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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1145 KiB

Open AccessArticle

Anti-TMV Activity of Malformin A₁, a Cyclic Penta-Peptide Produced by an Endophytic Fungus Aspergillus tubingensis FJBJ11

by Qing-Wei Tan, Fang-Luan Gao, Fu-Rong Wang and Qi-Jian Chen

Int. J. Mol. Sci. 2015, 16(3), 5750-5761; https://doi.org/10.3390/ijms16035750 - 12 Mar 2015

Cited by 34 | Viewed by 7616

Abstract

Plant-associated microorganisms are known to produce a variety of metabolites with novel structures and interesting biological activities. An endophytic fungus FJBJ11, isolated from the plant tissue of Brucea javanica (L.) Merr. (Simaroubaceae), was proven to be significantly effective in producing metabolites with anti- [...] Read more.

Plant-associated microorganisms are known to produce a variety of metabolites with novel structures and interesting biological activities. An endophytic fungus FJBJ11, isolated from the plant tissue of Brucea javanica (L.) Merr. (Simaroubaceae), was proven to be significantly effective in producing metabolites with anti-Tobacco mosaic virus (TMV) activities. The isolate was identified as Aspergillus tubingensis FJBJ11 based on morphological characteristics and ITS sequence. Bioassay-guided isolation led to the identification of a cycli penta-peptide, malformin A₁, along with two cyclic dipeptides, cyclo (Gly-l-Pro) and cyclo (Ala-Leu). Malformin A₁ showed potent inhibitory effect against the infection and replication of TMV with IC₅₀ values of 19.7 and 45.4 μg·mL⁻¹, as tested using local lesion assay and leaf-disc method, respectively. The results indicated the potential use of malformin A₁ as a leading compound or a promising candidate of new viricide. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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1082 KiB

Open AccessArticle

Role of Aeromonas hydrophila Flagella Glycosylation in Adhesion to Hep-2 Cells, Biofilm Formation and Immune Stimulation

by Susana Merino, Markus Wilhelms and Juan M. Tomás

Int. J. Mol. Sci. 2014, 15(12), 21935-21946; https://doi.org/10.3390/ijms151221935 - 28 Nov 2014

Cited by 20 | Viewed by 10006

Abstract

Polar flagellin proteins from Aeromonas hydrophila strain AH-3 (serotype O34) were found to be O-glycosylated with a heterogeneous heptasaccharide glycan. Two mutants with altered (light and strong) polar flagella glycosylation still able to produce flagella were previously obtained, as well as mutants [...] Read more.

Polar flagellin proteins from Aeromonas hydrophila strain AH-3 (serotype O34) were found to be O-glycosylated with a heterogeneous heptasaccharide glycan. Two mutants with altered (light and strong) polar flagella glycosylation still able to produce flagella were previously obtained, as well as mutants lacking the O34-antigen lipopolysaccharide (LPS) but with unaltered polar flagella glycosylation. We compared these mutants, altogether with the wild type strain, in different studies to conclude that polar flagella glycosylation is extremely important for A. hydrophila adhesion to Hep-2 cells and biofilm formation. Furthermore, the polar flagella glycosylation is an important factor for the immune stimulation of IL-8 production via toll receptor 5 (TLR5). Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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714 KiB

Open AccessArticle

Antioxidant and Immunoregulatory Activity of Polysaccharides from Quinoa (Chenopodium quinoa Willd.)

by Yang Yao, Zhenxing Shi and Guixing Ren

Int. J. Mol. Sci. 2014, 15(10), 19307-19318; https://doi.org/10.3390/ijms151019307 - 23 Oct 2014

Cited by 62 | Viewed by 9901

Abstract

The water-extractable (QWP) and the alkali-extractable (QAP) polysaccharides from quinoa (named QWP and QAP, respectively) and their four polysaccharide sub-fractions (QWP-1, QWP-2, QAP-1 and QAP-2), were isolated and purified by anion-exchange and gel filtration chromatography. QWP-1 and QWP-2 were composed of Rha, Ara, [...] Read more.

The water-extractable (QWP) and the alkali-extractable (QAP) polysaccharides from quinoa (named QWP and QAP, respectively) and their four polysaccharide sub-fractions (QWP-1, QWP-2, QAP-1 and QAP-2), were isolated and purified by anion-exchange and gel filtration chromatography. QWP-1 and QWP-2 were composed of Rha, Ara, Gal and GalA. QAP-1 and QAP-2 were composed of Rha, Ara, Man, Gal and GalA. Antioxidant and immunoregulatory activities of the polysaccharides were evaluated. The results showed that QWP-1, QWP-2, QAP-1 and QAP-2 had significant antioxidant and immunoregulatory activities. The results suggest that QWP-1, QWP-2, QAP-1 and QAP-2 could be used as potential antioxidants and immunomodulators. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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Review

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Open AccessReview

Bioactive Carbohydrates and Peptides in Foods: An Overview of Sources, Downstream Processing Steps and Associated Bioactivities

by Maria Hayes and Brijesh K. Tiwari

Int. J. Mol. Sci. 2015, 16(9), 22485-22508; https://doi.org/10.3390/ijms160922485 - 17 Sep 2015

Cited by 70 | Viewed by 10436

Abstract

Bioactive peptides and carbohydrates are sourced from a myriad of plant, animal and insects and have huge potential for use as food ingredients and pharmaceuticals. However, downstream processing bottlenecks hinder the potential use of these natural bioactive compounds and add cost to production [...] Read more.

Bioactive peptides and carbohydrates are sourced from a myriad of plant, animal and insects and have huge potential for use as food ingredients and pharmaceuticals. However, downstream processing bottlenecks hinder the potential use of these natural bioactive compounds and add cost to production processes. This review discusses the health benefits and bioactivities associated with peptides and carbohydrates of natural origin and downstream processing methodologies and novel processes which may be used to overcome these. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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2430 KiB

Open AccessReview

The Effects of Marine Carbohydrates and Glycosylated Compounds on Human Health

by Hee-Kyoung Kang, Chang Ho Seo and Yoonkyung Park

Int. J. Mol. Sci. 2015, 16(3), 6018-6056; https://doi.org/10.3390/ijms16036018 - 16 Mar 2015

Cited by 54 | Viewed by 8706

Abstract

Marine organisms have been recognized as a valuable source of bioactive compounds with industrial and nutraceutical potential. Recently, marine-derived carbohydrates, including polysaccharides and low molecular weight glycosylated oligosaccharides, have attracted much attention because of their numerous health benefits. Moreover, several studies have reported [...] Read more.

Marine organisms have been recognized as a valuable source of bioactive compounds with industrial and nutraceutical potential. Recently, marine-derived carbohydrates, including polysaccharides and low molecular weight glycosylated oligosaccharides, have attracted much attention because of their numerous health benefits. Moreover, several studies have reported that marine carbohydrates exhibit various biological activities, including antioxidant, anti-infection, anticoagulant, anti-inflammatory, and anti-diabetic effects. The present review discusses the potential industrial applications of bioactive marine carbohydrates for health maintenance and disease prevention. Furthermore, the use of marine carbohydrates in food, cosmetics, agriculture, and environmental protection is discussed. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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1989 KiB

Open AccessReview

Fatal Attraction: How Bacterial Adhesins Affect Host Signaling and What We Can Learn from Them

by Daniel H. Stones and Anne-Marie Krachler

Int. J. Mol. Sci. 2015, 16(2), 2626-2640; https://doi.org/10.3390/ijms16022626 - 23 Jan 2015

Cited by 44 | Viewed by 13516

Abstract

The ability of bacterial species to colonize and infect host organisms is critically dependent upon their capacity to adhere to cellular surfaces of the host. Adherence to cell surfaces is known to be essential for the activation and delivery of certain virulence factors, [...] Read more.

The ability of bacterial species to colonize and infect host organisms is critically dependent upon their capacity to adhere to cellular surfaces of the host. Adherence to cell surfaces is known to be essential for the activation and delivery of certain virulence factors, but can also directly affect host cell signaling to aid bacterial spread and survival. In this review we will discuss the recent advances in the field of bacterial adhesion, how we are beginning to unravel the effects adhesins have on host cell signaling, and how these changes aid the bacteria in terms of their survival and evasion of immune responses. Finally, we will highlight how the exploitation of bacterial adhesins may provide new therapeutic avenues for the treatment of a wide range of bacterial infections. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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952 KiB

Open AccessReview

Insight into the Molecular and Functional Diversity of Cnidarian Neuropeptides

by Toshio Takahashi and Noriyo Takeda

Int. J. Mol. Sci. 2015, 16(2), 2610-2625; https://doi.org/10.3390/ijms16022610 - 23 Jan 2015

Cited by 30 | Viewed by 8117

Abstract

Cnidarians are the most primitive animals to possess a nervous system. This phylum is composed of the classes Scyphozoa (jellyfish), Cubozoa (box jellyfish), and Hydrozoa (e.g., Hydra, Hydractinia), which make up the subphylum Medusozoa, as well as the class Anthozoa (sea [...] Read more.

Cnidarians are the most primitive animals to possess a nervous system. This phylum is composed of the classes Scyphozoa (jellyfish), Cubozoa (box jellyfish), and Hydrozoa (e.g., Hydra, Hydractinia), which make up the subphylum Medusozoa, as well as the class Anthozoa (sea anemones and corals). Neuropeptides have an early evolutionary origin and are already abundant in cnidarians. For example, from the cnidarian Hydra, a key model system for studying the peptides involved in developmental and physiological processes, we identified a wide variety of novel neuropeptides from Hydra magnipapillata (the Hydra Peptide Project). Most of these peptides act directly on muscle cells and induce contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. In this review, we describe FMRFamide-like peptides (FLPs), GLWamide-family peptides, and the neuropeptide Hym-355; FPQSFLPRGamide. Several hundred FLPs have been isolated from invertebrate animals such as cnidarians. GLWamide-family peptides function as signaling molecules in muscle contraction, metamorphosis, and settlement in cnidarians. Hym-355; FPQSFLPRGamide enhances neuronal differentiation in Hydra. Recently, GLWamide-family peptides and Hym-355; FPQSFLPRGamide were shown to trigger oocyte maturation and subsequent spawning in the hydrozoan jellyfish Cytaeis uchidae. These findings suggest the importance of these neuropeptides in both developmental and physiological processes. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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1358 KiB

Open AccessReview

Cellular Disulfide Bond Formation in Bioactive Peptides and Proteins

by Nitin A. Patil, Julien Tailhades, Richard Anthony Hughes, Frances Separovic, John D. Wade and Mohammed Akhter Hossain

Int. J. Mol. Sci. 2015, 16(1), 1791-1805; https://doi.org/10.3390/ijms16011791 - 14 Jan 2015

Cited by 53 | Viewed by 21871

Abstract

Bioactive peptides play important roles in metabolic regulation and modulation and many are used as therapeutics. These peptides often possess disulfide bonds, which are important for their structure, function and stability. A systematic network of enzymes—a disulfide bond generating enzyme, a disulfide bond [...] Read more.

Bioactive peptides play important roles in metabolic regulation and modulation and many are used as therapeutics. These peptides often possess disulfide bonds, which are important for their structure, function and stability. A systematic network of enzymes—a disulfide bond generating enzyme, a disulfide bond donor enzyme and a redox cofactor—that function inside the cell dictates the formation and maintenance of disulfide bonds. The main pathways that catalyze disulfide bond formation in peptides and proteins in prokaryotes and eukaryotes are remarkably similar and share several mechanistic features. This review summarizes the formation of disulfide bonds in peptides and proteins by cellular and recombinant machinery. Full article

(This article belongs to the Special Issue Bioactive Carbohydrates and Peptides)

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