Backbone Cyclised Peptides from Plants Show Molluscicidal Activity against the Rice Pest Pomacea canaliculata (Golden Apple Snail)

Abstract

Golden apple snails ( Pomacea canaliculata) are serious pests of rice in South East Asia. Cyclotides are backbone cyclized peptides produced by plants from Rubiaceae and Violaceae. In this study, we investigated the molluscicidal activity of cyclotides against golden apple snails. Crude cyclotide extracts from both Oldenlandia affinis and Viola odorata plants showed molluscicidal activity comparable to the synthetic molluscicide metaldehyde. Individual cyclotides from each extract demonstrated a range of molluscicidal activities. The cyclotides cycloviolacin O1, kalata B1, and kalata B2 were more toxic to golden apple snails than metaldehyde, while kalata B7 and kalata B8 did not cause significant mortality. The toxicity of the cyclotide kalata B2 on a nontarget species, the Nile tilapia ( Oreochromis niloticus), was three times lower than the common piscicide rotenone. Our findings suggest that the existing diversity of cyclotides in plants could be used to develop natural molluscicides.

Phosphatidylethanolamine Binding Is a Conserved Feature of Cyclotide-Membrane Interactions

“…Hemolytic Potency Correlates with Cyclotide-Membrane Binding, Insertion, and Permeabilization-Hemolytic assays at 37°C showed that cyclotides interact with and disrupt RBCs, with the hemolytic efficiency having the following order: cyO2 Ͼ kB2 ϳ kB6 Ͼ kB5 ϳ kB1 Ͼ kB9 Ͼ kB7 Ͼ kB8 Ͼ tcA. This trend is in agreement with previous studies in which a few cyclotides were examined for other biological activities (52)(53)(54). The relative hemolytic activity correlates with the relative leakage efficiency trend in POPC/POPE/Chol/SM model membranes (Fig.…”

Development and Evaluation of Poly Herbal Molluscicidal Extracts for Control of Apple Snail (Pomacea maculata)

“…The results indicated that D. elliptica and C. rotundus (LC 50 23.68 mg/L and 133.20 mg/L, respectively) showed the highest toxicity on GAS, while Vulgarone B, a sesquiterpene isolated from Artemisia douglasiana, showed 100% mortality of GAS at a concentration on par with metaldehyde [18]. The molluscicidal potency of methanol extract from neem seed (A. indica A. Juss), oleoresin of Zingiber officinale, and cyclotide extracts of Oldenlandia affinis and Viola odorata on GAS was ascertained [19][20][21][22]. The extract of neem leaves and garlic (Allium sativum) recorded more than 90% mortality at 1000 mg/L on GAS [23].…”

Semienzymatic Cyclization of Disulfide-rich Peptides Using Sortase A

“…Spectra were recorded with 2048 data points in the direct F 2 dimension and 600 increments in the indirect F 1 dimension. Additional spectra recorded for cyclo-[GGG]kB1[T] to be used in full structure calculations were NOESY with a 100-ms mixing time as well as E.COSY (56), DQF-COSY, and 13 C HSQC to produce the carbon chemical shifts. All spectra were processed using Topspin (Bruker) and analyzed by CCPNMR (57) and Xeasy (58).…”

“…Several rounds of AUTO, including additional restraints, such as disulfide bonds, hydrogen bonds, and dihedral angle restraints derived from TALOSϩ, were run to ensure correct peak assignment. H␣, HN, C␣, and C␤ chemical shifts derived from 1 H-1 H NOESY and 1 H- 13 C HSQC were used to generate and backbone dihedral angles using TALOSϩ (61). The ANNEAL function in CYANA was used to perform 10,000-step torsion angle dynamics to generate an ensemble from which 20 with the lowest penalty function were chosen for further analysis.…”

“…The combination of a cyclic backbone and a knotted arrangement of three disulfide bonds is known as the cyclic cystine knot motif, and this motif is believed to be responsible for the exceptional stability of cyclotides toward chemical, enzymatic, or thermal degradation (1). Although thought to have a natural function as defense molecules in plants via their pesticidal activities (11)(12)(13), cyclotides possess a range of pharmaceutically interesting biological activities, including uterotonic (2), anti-HIV (14), antimicrobial (15), and insecticidal (11,16) activities, and are cytotoxic to tumor cells (17,18). Thousands of cyclotides are thought to exist in nature, and more than 250 sequences have been described so far (see the CyBase Web site) (19), making them one of the most abundant plant protein families discovered.…”