Identification of Novel d-Amino Acid Oxidase Inhibitors by in Silico Screening and Their Functional Characterization in Vitro

2013 ◽  
Vol 56 (5) ◽  
pp. 1894-1907 ◽  
Author(s):  
Masumi Katane ◽  
Naoko Osaka ◽  
Satsuki Matsuda ◽  
Kazuhiro Maeda ◽  
Tomonori Kawata ◽  
...  
2021 ◽  
Author(s):  
Li Bo ◽  
Yan Xiong ◽  
Qiyi He ◽  
Xiaodong Yu ◽  
Bo Li ◽  
...  

Abstract The anti-tumor potential of animal toxins has fully attracted the attention of researchers. Snake venoms is a complex mixture of different components and has revealed high toxicity on normal and tumoral tissues or cells. The snake venom L-Amino-acid oxidase (svLAAO) has grown up to be a critical research target in molecular biology sciences and medicine sciences since widespread presence and various biological roles, including antitumor application. We found that Crotalus adamanteus (C. adamanteus) venom LAAO significantly decreased the viability of ovarian cancer cells and caused morphological changes preceded cell death. Cell experiments confirmed that C. adamanteus venom LAAO caused alterations of intrinsic or extrinsic apoptosis pathway-related genes in ovarian cancer cells. Animal experiments and histological analysis also proved that C. adamanteus venom LAAO could effectively inhibit the damage of ovarian cancer to tissues. The major apoptosis induction of C. adamanteus venom LAAO on ovarian cancer cells can be blocked by catalase, suggesting that the cytotoxicity of C. adamanteus venom LAAO on ovarian cancer cells was mainly mediated by H2O2. Our preliminary results revealed that C. adamanteus venom LAAO may induce apoptosis of ovarian cancer cells through the death receptor pathway and mitochondrial pathway. It is inferred that C. adamanteus venom LAAO will be some advantages in New Drug Research and Development of antitumor drugs in the future. Nevertheless, extra studies on the pharmacological actions and molecular mechanism of svLAAO in anti-cancer are necessary in order to better promote its application.


Toxicon ◽  
2017 ◽  
Vol 139 ◽  
pp. 20-30 ◽  
Author(s):  
Kok Keong Tan ◽  
Siok Ghee Ler ◽  
Jayantha Gunaratne ◽  
Boon Huat Bay ◽  
Gopalakrishnakone Ponnampalam

2014 ◽  
Vol 8 (3) ◽  
pp. 149-154 ◽  
Author(s):  
Miho Shishikura ◽  
Hitomi Hakariya ◽  
Sumiko Iwasa ◽  
Takashi Yoshio ◽  
Hideaki Ichiba ◽  
...  

2012 ◽  
Vol 102 (11) ◽  
pp. 1054-1063 ◽  
Author(s):  
Chi-Hua Cheng ◽  
Chia-Ann Yang ◽  
Kou-Cheng Peng

Previous studies have shown that the extracellular proteins of Trichoderma harzianum ETS 323 grown in the presence of deactivated Botrytis cinerea in culture include a putative l-amino acid oxidase and have suggested the involvement of this enzyme in the antagonistic mechanism. Here, we hypothesized that the mycoparasitic process of Trichoderma spp. against B. cinerea involves two steps; that is, an initial hyphal coiling stage and a subsequent hyphal coiling stage, with different coiling rates. The two-step antagonism of T. harzianum ETS 323 against B. cinerea during the mycoparasitic process in culture was evaluated using a biexponential equation. In addition, an l-amino acid oxidase (Th-l-AAO) was identified from T. harzianum ETS 323. The secretion of Th-l-AAO was increased when T. harzianum ETS 323 was grown with deactivated hyphae of B. cinerea. Moreover, in vitro assays indicated that Th-l-AAO effectively inhibited B. cinerea hyphal growth, caused cytosolic vacuolization in the hyphae, and led to hyphal lysis. Th-l-AAO also showed disease control against the development of B. cinerea on postharvest apple fruit and tobacco leaves. Furthermore, an apoptosis-like response, including the generation of reactive oxygen species, was observed in B. cinerea after treatment with Th-l-AAO, suggesting that Th-l-AAO triggers programmed cell death in B. cinerea. This may be associated with the two-step antagonism of T. harzianum ETS 323 against B. cinerea.


2013 ◽  
Author(s):  
Maritza Fernández Culma ◽  
Jaime A Pereañez ◽  
Vitelbina Núñez Rangel ◽  
Bruno Lomonte

Bothrops punctatus is an endangered, semi-arboreal pitviper species distributed in Panamá, Colombia, and Ecuador, whose venom is poorly characterized. In the present work, the protein composition of this venom was profiled using the 'snake venomics' analytical strategy. Decomplexation of the crude venom by RP-HPLC and SDS-PAGE, followed by tandem mass spectrometry of tryptic digests, showed that it consists of proteins assigned to at least nine snake toxin families. Metalloproteinases are predominant in this secretion (41.5% of the total proteins), followed by C-type lectin/lectin-like proteins (16.7%), bradykinin-potentiating peptides (10.7%), phospholipases A2 (9.3%), serine proteinases (5.4%), disintegrins (3.8%), L-amino acid oxidases (3.1%), vascular endothelial growth factors (1.7%), and cysteine-rich secretory proteins (1.2%). Altogether, 6.6% of the proteins were not identified. In vitro, the venom exhibited proteolytic, phospholipase A2, and L-amino acid oxidase activities, as well as angiotensin-converting enzyme (ACE)-inhibitory activity, in agreement with the obtained proteomic profile. Cytotoxic activity on murine C2C12 myoblasts was negative, suggesting that the majority of venom phospholipases A2 likely belong to the acidic type, which often lack major toxic effects. The protein composition of B. punctatus venom shows a good correlation with toxic activities here and previously reported, and adds further data in support of the wide diversity of strategies that have evolved in snake venoms to subdue prey, as increasingly being revealed by proteomic analyses.


2020 ◽  
Author(s):  
Maurício Aurelio Gomes Heleno ◽  
João Ernesto de Carvalho ◽  
Alexandre Nowill ◽  
Luis Alberto Ponce-Soto

AbstractIn this work we describe the isolation of a new isoform L-amino acid oxidase (LAAO) referred to as Balt-LAAO-II from Bothrops alternatus snake venom, which was highly purified using a combination of molecular exclusion (Sephadex G-75) and RP-HPLC chromatographics steps. When analyzed by SDS-PAGE, the purified Balt-LAAO-II presented a molecular weight of ∼66 kDa. The N-terminal amino acid sequence and internal peptide sequences showed close structural homology to other snake venom L-amino acid oxidases.This enzyme induces in vitro cytotoxicity on cultured human leukemic HL60 cells. Cells were grown in RPMI medium and were incubated with isoform Balt-LAAO-II (1, 10 and 100 μg/mL) for up to 72 h. All three concentrations of venom markedly decreased the cell viability from 6 h onwards based on the staining with propidium iodide, the reduction of 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and the uptake of neutral red.Flow cytometry showed that all isoform Balt-LAAO-II and whole venom concentrations induced apoptosis after 2-6 h of incubation. Morphological analysis of cells incubated with isoform Balt-LAAO-II and whole venom showed cell rounding and lysis that increased with the venom concentration and duration of incubation. These results show that isoform Balt-LAAO-II from venom Bothrops alternatus is cytotoxic to cultured HL60 cells and suggest that this damage may involve apoptotic and oxidative stress pathways.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Aditya K. Padhi ◽  
Kam Y. J. Zhang

Abstract Impaired enzymatic activity in D-amino acid oxidase (DAAO) caused by missense mutations has been shown to trigger amyotrophic lateral sclerosis (ALS) through an abnormal accumulation of D-serine in the spinal cord. While loss of enzymatic functions of certain ALS-causing DAAO variants have been studied before, a detailed understanding of structure-dynamics-function relationship of the rare DAAO variants has not been investigated hitherto. To address this, we carried out a comprehensive study of all the reported rare DAAO variants. By employing a spectrum of bioinformatics analyses along with extensive structural dynamics simulations, we show that certain rare variants disrupted key interactions with the active site and decreased the conformational flexibility of active site loop comprising residues 216–228, which is essential for substrate binding and product release. Moreover, these variants lost crucial interactions with the cofactor flavin-adenine-dinucleotide, resulting in weaker binding affinity. A detailed inspection revealed that these variants exhibited such characteristics due to the abrogation of specific salt bridges. Taken together, our study provides a gateway into the structural-dynamic features of the rare DAAO variants and highlights the importance of informatics-based integrated analyses in the screening and prioritization of variants a priori to the clinical-functional characterization.


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