Morintides: cargo-free chitin-binding peptides from Moringa oleifera.

BACKGROUND: Hevein-like peptides are a family of cysteine-rich and chitin-binding peptides consisting of 29-45 amino acids. Their chitin-binding property is essential for plant defense against fungi. Based on the number of cysteine residues in their sequences, they are divided into three sub-families: 6C-, 8C- and 10C-hevein-like peptides. All three subfamilies contain a three-domain precursor comprising a signal peptide, a mature hevein-like peptide and a C-terminal domain comprising a hinge region with protein cargo in 8C- and 10C-hevein-like peptides. RESULTS: Here we report the isolation and characterization of two novel 8C-hevein-like peptides, designated morintides (mO1 and mO2), from the drumstick tree Moringa oleifera, a drought-resistant tree belonging to the Moringaceae family. Proteomic analysis revealed that morintides comprise 44 amino acid residues and are rich in cysteine, glycine and hydrophilic amino acid residues such as asparagine and glutamine. Morintides are resistant to thermal and enzymatic degradation, able to bind to chitin and inhibit the growth of phyto-pathogenic fungi. Transcriptomic analysis showed that they contain a three-domain precursor comprising an endoplasmic reticulum (ER) signal sequence, a mature peptide domain and a C-terminal domain. A striking feature distinguishing morintides from other 8C-hevein-like peptides is a short and protein-cargo-free C-terminal domain. Previously, a similar protein-cargo-free C-terminal domain has been observed only in ginkgotides, the 8C-hevein-like peptides from a gymnosperm Ginkgo biloba. Thus, morintides, with a cargo-free C-terminal domain, are a stand-alone class of 8C-hevein-like peptides from angiosperms. CONCLUSIONS: Our results expand the existing library of hevein-like peptides and shed light on molecular diversity within the hevein-like peptide family. Our work also sheds light on the anti-fungal activity and stability of 8C-hevein-like peptides.

Studies on the Chitin Binding Property of Novel Cysteine-Rich Peptides from Alternanthera sessilis.

Hevein-like peptides make up a family of cysteine-rich peptides (CRPs) and play a role in plants in their defense against insects and fungal pathogens. In this study, we report the isolation and characterization of six hevein-like peptides, aSG1-G3 and aSR1-R3, collectively named altides from green and red varieties of Alternanthera sessilis, a perennial herb belonging to the Amaranthaceae family. Proteomic analysis of altides revealed they contain six cysteines (6C), seven glycines, four prolines, and a conserved chitin-binding domain (SXYGY/SXFGY). Thus far, only four 6C-hevein-like peptides have been isolated and characterized; hence, our study expands the existing library of these peptides. Nuclear magnetic resonance (NMR) study of altides showed its three disulfide bonds were arranged in a cystine knot motif. As a consequence of this disulfide arrangement, they are stable against thermal and enzymatic degradation. Gene cloning studies revealed altides contain a three-domain precursor with an endoplasmic reticulum signal peptide followed by a mature CRP domain and a short C-terminal tail. This indicates that the biosynthesis of altides is through the secretory pathway. (1)H NMR titration experiments showed that the 29-30-amino acid altides bind to chitin oligomers with dissociation constants in the micromolar range. Aromatic residues in the chitin-binding domain of altides were involved in the binding interaction. To the best of our knowledge, aSR1 is the smallest hevein-like peptide with a dissociation constant toward chitotriose comparable to those of hevein and other hevein-like peptides. Together, our study expands the existing library of 6C-hevein-like peptides and provides insights into their structure, biosynthesis, and interaction with chitin oligosaccharides.

Clinical studies in Ayurveda: A bibliometric analysis of articles indexed in AYUSH research portal.

Bibliometric analysis is a standard method for evaluating the quality and quantity of published articles. AYUSH research portal (ARP) is meant for the dissemination of research findings in the domains of Ayurveda, Yoga and Naturopathy, Unani, Siddha, Sowa-rigpa, and Homoeopathy and allied faculties. The study attempts to understand the trend of published Ayurveda clinical trial-based articles in terms of quality and quantity. Three perspectives of research output assessed in this study are productivity in the field of Ayurveda, evidence from articles, and its involvement with the body system where disease or malfunctions are induced. Based on the study, it is observed that the highest number of articles have been published under the musculoskeletal, endocrine/metabolic/nutritional categories, and skin. Further, it is observed that only 4.50% of articles are categorized under the evidence of Grade "A" (randomized controlled trials [RCTs]) as per the World Health Organization's traditional medicine research guidelines. Out of the top 20 journals which publish Ayurveda-based research works, only five journals are indexed in reputed indexing platforms viz., PubMed and Scopus. The findings indicate that, Ayurveda clinical trials have to be planned meticulously and carried out as per the RCT guidelines for producing quality evidence so that the abysmal percentage of grade-A category articles will increase in ARP. Further, the journals, which are not yet indexed in standard indexing platforms, must strive to secure a place in them to ensure access to appropriate peers and effective dissemination of findings.

Vaccatides: Antifungal Glutamine-Rich Hevein-Like Peptides from Vaccaria hispanica.

Hevein and hevein-like peptides are disulfide-constrained chitin-binding cysteine-rich peptides. They are divided into three subfamilies, 6C-, 8C-, and 10C-hevein-like peptides, based on the number of cysteine residues. In addition, hevein-like peptides can exist in two forms, short and long. The long C-terminal form found in hevein and 10C-hevein-like peptides contain a C-terminal protein cargo. In contrast, the short form without a protein cargo is found in all three subfamilies. Here, we report the discovery and characterization of two novel glutamine-rich and protein cargo-free 8C-hevein-like peptides, vaccatides vH1 and vH2, from Vaccaria hispanica of the Caryophyllaceae family. Proteomic analyses showed that the vaccatides are 40-41 amino acids in length and contain a chitin-binding domain. NMR determination revealed that vaccatide vH2 displays a highly compact structure with a N-terminal cystine knot and an addition C-terminal disulfide bond. Stability studies showed that this compact structure renders vaccatide vH2 resistant to thermal, chemical and proteolytic degradation. The chitin-binding vH2 was shown to inhibit the mycelium growth of four phyto-pathogenic fungal strains with IC50 values in the micromolar range. Our findings show that vaccatides represent a new family of 8C-hevein-like peptides, which are protein cargo-free and glutamine-rich, characteristics that differentiate them from the prototypic hevein and the 10C-hevein-like peptides. In summary, this study enriches the existing library of hevein-like peptides and provides insight into their molecular diversity in sequence, structure and biosynthesis. Additionally, their highly disulfide-constrained structure could be used as a scaffold for developing metabolically and orally active peptidyl therapeutics.

Supraclavicular nodal failure in patients with one to three positive axillary lymph nodes treated with breast conserving surgery and breast irradiation, without supraclavicular node radiation.

The purpose of this study was to evaluate the risk factors associated with supraclavicular nodal failure (SCF) in patients with one to three positive axillary nodes treated with breast conserving surgery and axillary dissection without supraclavicular node radiation (S/C RT) to aid in the selection of patients for S/C RT. Two hundred two breast conservation patients with one to three positive axillary nodes on axillary dissection treated with breast irradiation without S/C RT and 20 patients with S/C RT between August 1985 and May 2002 were identified and retrospectively evaluated. The Kaplan-Meier method was used to determine SCF-free and overall survival curves. Risk factors for SCF were examined. The median follow-up from surgery was 72 months (range: 4-195). Nine of 202 patients (4%) failed in the ipsilateral breast, 4 (2%) in the ipsilateral supraclavicular lymph nodes, 4 (2%) in the ipsilateral axillary and/or internal mammary nodes and 30 (15%) distantly. The 5- and 10-year SCF-free survival was 97.92%. The overall survival at 5, 10, and 15 years was 91.35%, 75.58%, and 67.18%, respectively. SCFs were associated with high grade or ER negative cancers, but not with number of positive nodes. Two of the four SCFs were associated with distant metastases, and two with local failures. One patient with a SCF was salvaged and is disease-free at 134 months. The overall low incidence of SCF in patients with one to three positive nodes treated with breast radiation alone after breast conserving surgery and adequate axillary dissection suggests that additional S/C RT is unnecessary in this cohort. When it occurs, supraclavicular nodal failure is often associated with distant metastases.