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Koizumi Y, Fukushima J, Kobayashi Y, Kadowaki A, Natsui M, Yamaguchi T, Imai Y, Sugiyama T, Kuba K. Genome-Scale CRISPR/Cas9 Screening Reveals Squalene Epoxidase as a Susceptibility Factor for Cytotoxicity of Malformin A1. Chembiochem 2019; 20:1563-1568. [PMID: 30734978 PMCID: PMC6618319 DOI: 10.1002/cbic.201800769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/21/2019] [Indexed: 01/23/2023]
Abstract
Malformin A1 (MA1) is a fungus-produced cyclic pentapeptide. MA1 exhibits teratogenicity to plants, fibrinolysis-enhancing activity, and cytotoxicity to mammalian cells. To clarify the cytotoxic mechanism of MA1, we screened for the genes involved in the cytotoxicity of MA1 in monocytoid U937 cells by using a CRISPR/Cas9-based genome-wide knockout library. Screening was performed by positive selection for cells that were resistant to MA1 treatment, and single guide RNAs (sgRNAs) integrated into MA1-resistant cells were analyzed by high-throughput sequencing. As a result of the evaluation of sgRNAs that were enriched in MA1-resistant cells, SQLE, which encodes squalene epoxidase, was identified as a candidate gene. SQLE-depleted U937 cells were viable in the presence of MA1, and squalene epoxidase inhibitor conferred MA1 resistance to wild-type cells. These results indicate that squalene epoxidase is implicated in the cytotoxicity of MA1. This finding represents a new insight into applications of MA1 for treating ischemic diseases.
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Affiliation(s)
- Yukio Koizumi
- Department of Biochemistry and Metabolic ScienceAkita University Graduate School of Medicine1-1-1 HondoAkita 010-8543Japan
| | - Jun Fukushima
- Department of BiotechnologyFaculty of Bioresource SciencesAkita Prefectural University241–438 Kaidobata-Nishi, Shimoshinjo-NakanoAkita010–0195Japan
| | - Yayoi Kobayashi
- Department of BiotechnologyFaculty of Bioresource SciencesAkita Prefectural University241–438 Kaidobata-Nishi, Shimoshinjo-NakanoAkita010–0195Japan
| | - Ayumi Kadowaki
- Department of Biochemistry and Metabolic ScienceAkita University Graduate School of Medicine1-1-1 HondoAkita 010-8543Japan
| | - Miyuki Natsui
- Department of Biochemistry and Metabolic ScienceAkita University Graduate School of Medicine1-1-1 HondoAkita 010-8543Japan
| | - Tomokazu Yamaguchi
- Department of Biochemistry and Metabolic ScienceAkita University Graduate School of Medicine1-1-1 HondoAkita 010-8543Japan
| | - Yumiko Imai
- Laboratory of Regulation of Intractable Infectious DiseasesNational Institutes of Biomedical Innovation, Health and Nutrition7-6-8 Saito-AsagiIbaraki, Osaka567-0085Japan
| | - Toshihiro Sugiyama
- Department of Biochemistry and Metabolic ScienceAkita University Graduate School of Medicine1-1-1 HondoAkita 010-8543Japan
| | - Keiji Kuba
- Department of Biochemistry and Metabolic ScienceAkita University Graduate School of Medicine1-1-1 HondoAkita 010-8543Japan
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Koizumi Y, Nagai K, Gao L, Koyota S, Yamaguchi T, Natsui M, Imai Y, Hasumi K, Sugiyama T, Kuba K. Involvement of RSK1 activation in malformin-enhanced cellular fibrinolytic activity. Sci Rep 2018; 8:5472. [PMID: 29615689 PMCID: PMC5882963 DOI: 10.1038/s41598-018-23745-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 03/15/2018] [Indexed: 12/03/2022] Open
Abstract
Pharmacological interventions to enhance fibrinolysis are effective for treating thrombotic disorders. Utilizing the in vitro U937 cell line-based fibrin degradation assay, we had previously found a cyclic pentapeptide malformin A1 (MA1) as a novel activating compound for cellular fibrinolytic activity. The mechanism by which MA1 enhances cellular fibrinolytic activity remains unknown. In the present study, we show that RSK1 is a crucial mediator of MA1-induced cellular fibrinolysis. Treatment with rhodamine-conjugated MA1 showed that MA1 localizes mainly in the cytoplasm of U937 cells. Screening with an antibody macroarray revealed that MA1 induces the phosphorylation of RSK1 at Ser380 in U937 cells. SL0101, an inhibitor of RSK, inhibited MA1-induced fibrinolytic activity, and CRISPR/Cas9-mediated knockout of RSK1 but not RSK2 suppressed MA1-enhanced fibrinolysis in U937 cells. Synthetic active MA1 derivatives also induced the phosphorylation of RSK1. Furthermore, MA1 treatment stimulated phosphorylation of ERK1/2 and MEK1/2. PD98059, an inhibitor of MEK1/2, inhibited MA1-induced phosphorylation of RSK1 and ERK1/2, indicating that MA1 induces the activation of the MEK-ERK-RSK pathway. Moreover, MA1 upregulated the expression of urokinase-type plasminogen activator (uPA) and increased uPA secretion. These inductions were abrogated in RSK1 knockout cells. These results indicate that RSK1 is a key regulator of MA1-induced extracellular fibrinolytic activity.
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Affiliation(s)
- Yukio Koizumi
- Department of Biochemistry and Metabolic Science, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
| | - Kenichiro Nagai
- School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Lina Gao
- Department of Biochemistry and Metabolic Science, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan
| | - Souichi Koyota
- Molecular Medicine Laboratory, Bioscience Education and Research Support Center, Akita University, 1-1-1 Hondo, Akita, 010-8543, Japan
| | - Tomokazu Yamaguchi
- Department of Biochemistry and Metabolic Science, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan
| | - Miyuki Natsui
- Department of Biochemistry and Metabolic Science, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan
| | - Yumiko Imai
- Laboratory of Regulation of Intractable Infectious Diseases, National Institute of Biomedical Innovation, Health and Nutrition, 7-6-8 Saito-Asagi, Ibaraki, Osaka, 567-0085, Japan
| | - Keiji Hasumi
- Department of Applied Biological Science, Tokyo Noko University, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Toshihiro Sugiyama
- Department of Biochemistry and Metabolic Science, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan
| | - Keiji Kuba
- Department of Biochemistry and Metabolic Science, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan
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Park SY, Oh HH, Park YL, Yu HM, Myung DS, Cho SB, Lee WS, Park D, Joo YE. Malformin A1 treatment alters invasive and oncogenic phenotypes of human colorectal cancer cells through stimulation of the p38 signaling pathway. Int J Oncol 2017; 51:959-966. [PMID: 28713983 DOI: 10.3892/ijo.2017.4070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 07/03/2017] [Indexed: 11/05/2022] Open
Abstract
Malformin A1 (MA1), a cyclic pentapeptide isolated from Aspergillus niger, has been found to possess a range of bioactive properties including antibacterial activity. However, it is unclear whether MA1 exerts an anticancer effect or not. In this study, we conducted in vitro experiments to investigate its anticancer properties in human colorectal cancer cells. The effect of MA1 on human colorectal cancer cells, SW480 and DKO1, was examined by the WST-1 cell viability assay, inverted microscopy, 5-bromo-2-deoxyuridine (BrdU) incorporation, flow cytometry, DNA fragmentation, wound healing, Transwell assays, and western blotting. MA1 treatment showed potent cytotoxic activities on human colorectal cancer cells. MA1 treatment induced apoptosis by activating the poly(ADP-ribose) polymerase (PARP), caspase‑3, -7, and -9. MA1 treatment led to the increase in p53 upregulated modulator of apoptosis (PUMA) and the decrease in X-linked inhibitor of apoptosis protein (XIAP) and Survivin. In addition, MA1 treatment induced cell cycle arrest in the sub-G1 phase. The pan-caspase inhibitor, Z‑VAD‑FMK, attenuated these MA1-induced apoptotic effects on human colorectal cancer cells. Moreover, MA1 treatment suppressed tumor cell migration and invasion. The phosphorylation level of p38 was upregulated by MA1 treatment, and the inhibitor of p38, SB203580, attenuated the MA1-induced p38 phosphorylation as well as caspase‑3 and PARP activation. These results indicate that MA1 treatment alters invasive and oncogenic phenotypes of human colorectal cancer cells through the stimulation of the p38 signaling pathway.
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Affiliation(s)
- Sun-Young Park
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757, Republic of Korea
| | - Hyung-Hoon Oh
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757, Republic of Korea
| | - Young-Lan Park
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757, Republic of Korea
| | - Hyung-Min Yu
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757, Republic of Korea
| | - Dae-Seong Myung
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757, Republic of Korea
| | - Sung-Bum Cho
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757, Republic of Korea
| | - Wan-Sik Lee
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757, Republic of Korea
| | - Daeho Park
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Young-Eun Joo
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757, Republic of Korea
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Carvalho A, Chu J, Meinguet C, Kiss R, Vandenbussche G, Masereel B, Wouters J, Kornienko A, Pelletier J, Mathieu V. A harmine-derived beta-carboline displays anti-cancer effects in vitro by targeting protein synthesis. Eur J Pharmacol 2017; 805:25-35. [PMID: 28322844 DOI: 10.1016/j.ejphar.2017.03.034] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 03/13/2017] [Accepted: 03/15/2017] [Indexed: 12/17/2022]
Abstract
Growing evidence indicates that protein synthesis is deregulated in cancer onset and progression and targeting this process might be a selective way to combat cancers. While harmine is known to inhibit DYRK1A and intercalate into the DNA, tri-substitution was shown previously to modify its activity profile in favor of protein synthesis inhibition. In this study, we thus evaluated the optimized derivative CM16 in vitro anti-cancer effects unfolding its protein synthesis inhibition activity. Indeed, the growth inhibitory profile of CM16 in the NCI 60-cancer-cell-line-panel correlated with those of other compounds described as protein synthesis inhibitors. Accordingly, CM16 decreased in a time- and concentration-dependent manner the translation of neosynthesized proteins in vitro while it did not affect mRNA transcription. CM16 rapidly penetrated into the cell in the perinuclear region of the endoplasmic reticulum where it appears to target translation initiation as highlighted by ribosomal disorganization. More precisely, we found that the mRNA expression levels of the initiation factors EIF1AX, EIF3E and EIF3H differ when comparing resistant or sensitive cell models to CM16. Additionally, CM16 induced eIF2α phosphorylation. Those effects could explain, at least partly, the CM16 cytostatic anti-cancer effects observed in vitro while neither cell cycle arrest nor DNA intercalation could be demonstrated. Therefore, targeting protein synthesis initiation with CM16 could represent a new promising alternative to current cancer therapies due to the specific alterations of the translation machinery in cancer cells as recently evidenced with respect to EIF1AX and eIF3 complex, the potential targets identified in this present study.
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Affiliation(s)
- Annelise Carvalho
- Laboratoire de Cancérologie et Toxicologie Expérimentale, Faculté de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
| | - Jennifer Chu
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
| | - Céline Meinguet
- Namur Medicine and Drug Innovation Center (NAMEDIC-NARILIS), Université de Namur, Namur, Belgium
| | - Robert Kiss
- Laboratoire de Cancérologie et Toxicologie Expérimentale, Faculté de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
| | - Guy Vandenbussche
- Laboratory for the Structure and Function of Biological Membranes, Faculté des Sciences, Université Libre de Bruxelles, Brussels, Belgium
| | - Bernard Masereel
- Namur Medicine and Drug Innovation Center (NAMEDIC-NARILIS), Université de Namur, Namur, Belgium
| | - Johan Wouters
- Namur Medicine and Drug Innovation Center (NAMEDIC-NARILIS), Université de Namur, Namur, Belgium
| | - Alexander Kornienko
- Department of Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
| | - Véronique Mathieu
- Laboratoire de Cancérologie et Toxicologie Expérimentale, Faculté de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium.
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Koizumi Y, Nagai K, Hasumi K, Kuba K, Sugiyama T. Structure-activity relationship of cyclic pentapeptide malformins as fibrinolysis enhancers. Bioorg Med Chem Lett 2016; 26:5267-5271. [PMID: 27680590 DOI: 10.1016/j.bmcl.2016.09.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 09/14/2016] [Accepted: 09/16/2016] [Indexed: 11/17/2022]
Abstract
The formation of blood clots in blood vessels causes severe ischemic diseases such as cerebral infarction and myocardial infarction. While searching for microbial products that increase fibrinolytic activity using an in vitro fibrin degradation assay, we found malformin A1, a disulfide form of cyclo(-d-Cys-d-Cys-l-Val-d-Leu-l-Ile-), as an active compound. In this study, we synthesized malformin derivatives using a solid-phase peptide synthesis method and evaluated their fibrinolytic activity and cytotoxicity. Reduction of the disulfide bond and linearization of the cyclic peptide frame decreased the pro-fibrinolytic activity. Substitution of a branched-chain amino acid with lysine resulted in loss of activity. However, protection of the amino group in the lysine derivatives by the tert-butoxycarbonyl (Boc) group rescued the inactivity. Furthermore, the phenylalanine derivatives also exhibited a similar pro-fibrinolytic effect compared to malformin A1. These results suggest that the disulfide bond, the cyclic peptide frame, and the bulky hydrophobic side chains play a crucial role in the pro-fibrinolytic activity of malformin. The effective dose of the active derivatives for the in vitro fibrin degradation showed similar ranges (1-5μM), while the order of cytotoxic potency for the active derivatives was as follows: Phe-derivatives>BocLys-derivatives>malformin A1>reduced form. These results showed no correlation between pro-fibrinolytic activity and cytotoxicity, suggesting the possibility of the synthesis for non-toxic malformin derivatives possessing the activity.
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Affiliation(s)
- Yukio Koizumi
- Department of Biochemistry, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
| | - Kenichiro Nagai
- School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Keiji Hasumi
- Department of Applied Biological Science, Tokyo Noko University, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Keiji Kuba
- Department of Biochemistry, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
| | - Toshihiro Sugiyama
- Department of Biochemistry, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
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Malformin A1 promotes cell death through induction of apoptosis, necrosis and autophagy in prostate cancer cells. Cancer Chemother Pharmacol 2015; 77:63-75. [PMID: 26645406 DOI: 10.1007/s00280-015-2915-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/09/2015] [Indexed: 10/22/2022]
Abstract
PURPOSE Malformin A1 (MA1), a cyclopentapeptide isolated from fungal origin, has been identified to induce varieties of intriguing biological activities. Here, we reported the mode of mechanism underlying MA1-mediated cytotoxicity through induction of apoptosis, necrosis and autophagy in prostate cancer (PCa) cells. METHODS Human PCa cells PC3 and LNCaP were treated with MA1, and cell viability, apoptosis, necrosis, mitochondrial damage, oxidative stress and autophagy were analyzed, respectively. Pharmacological inhibitors, transient transfection of plasmids and siRNAs were then used to identify the roles of oxidative stress and autophagy in MA1-triggered cell death. RESULTS In both PC3 and LNCaP cells, MA1 inhibited cell proliferation and triggered oxidative stress via the rapid accumulation of reactive oxygen species and a decrease in mitochondrial transmembrane potential. Mitochondrial damage by MA1 triggered caspase activation and intracellular ATP deletion, leading to apoptosis and necrosis, respectively. Meanwhile, MA1 activated autophagy as indicated by conversion of LC3BI to LC3BII and increased GFP-tagged LC3B punctate dots. Pharmacological inhibition of autophagy or knocking down LC3B attenuated MA1-mediated cell death. Excessive oxidative stress and decreased ATP stimulated AMPK/mTOR pathway, which led to induction of MA1-mediated autophagy. CONCLUSIONS Coaction of apoptotic, necrotic and autophagic cell death induced by mitochondrial damage defines a novel mechanism contributing to the growth suppression of MA1 in prostate cancer cells, and activation of autophagy might be a potential strategy for improving its chemotherapeutic effects.
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Wang J, Jiang Z, Lam W, Gullen EA, Yu Z, Wei Y, Wang L, Zeiss C, Beck A, Cheng EC, Wu C, Cheng YC, Zhang Y. Study of Malformin C, a Fungal Source Cyclic Pentapeptide, as an Anti-Cancer Drug. PLoS One 2015; 10:e0140069. [PMID: 26540166 PMCID: PMC4635020 DOI: 10.1371/journal.pone.0140069] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 09/20/2015] [Indexed: 11/25/2022] Open
Abstract
Malformin C, a fungal cyclic pentapeptide, has been claimed to have anti-cancer potential, but no in vivo study was available to substantiate this property. Therefore, we conducted in vitro and in vivo experiments to investigate its anti-cancer effects and toxicity. Our studies showed Malformin C inhibited Colon 38 and HCT 116 cell growth dose-dependently with an IC50 of 0.27±0.07μM and 0.18±0.023μM respectively. This inhibition was explicated by Malformin C’s effect on G2/M arrest. Moreover, we observed up-regulated expression of phospho-histone H2A.X, p53, cleaved CASPASE 3 and LC3 after Malformin C treatment, while the apoptosis assay indicated an increased population of necrotic and late apoptotic cells. In vivo, the pathological study exhibited the acute toxicity of Malformin C at lethal dosage in BDF1 mice might be caused by an acute yet subtle inflammatory response, consistent with elevated IL-6 in the plasma cytokine assay. Further anti-tumor and toxicity experiments proved that 0.3mg/kg injected weekly was the best therapeutic dosage of Malformin C in Colon 38 xenografted BDF1 mice, whereas 0.1mg/kg every other day showed no effect with higher resistance, and 0.9mg/kg per week either led to fatal toxicity in seven-week old mice or displayed no advantage over 0.3mg/kg group in nine-week old mice. Overall, we conclude that Malformin C arrests Colon 38 cells in G2/M phase and induces multiple forms of cell death through necrosis, apoptosis and autophagy. Malformin C has potent cell growth inhibition activity, but the therapeutic index is too low to be an anti-cancer drug.
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Affiliation(s)
- Jing Wang
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Oncology and Hematology, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Zaoli Jiang
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Wing Lam
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Elizabeth A. Gullen
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Zhe Yu
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Ying Wei
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Lihui Wang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Caroline Zeiss
- Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Amanda Beck
- Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Ee-Chun Cheng
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Chunfu Wu
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Yung-Chi Cheng
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail: (YCC); (YZ)
| | - Yixuan Zhang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
- * E-mail: (YCC); (YZ)
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Anti-TMV activity of malformin A1, a cyclic penta-peptide produced by an endophytic fungus Aspergillus tubingensis FJBJ11. Int J Mol Sci 2015; 16:5750-61. [PMID: 25775156 PMCID: PMC4394503 DOI: 10.3390/ijms16035750] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/03/2015] [Accepted: 03/07/2015] [Indexed: 11/17/2022] Open
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-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.
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