• Journal of the Korean Magnetic Resonance Society
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• v.11 no.1
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• pp.10-23
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• 2007

A new disintegrin protein named saxatilin was purified from Korean snake venom (Gloydius saxatilis). Saxatilin is a 73 residue small ploypeptide, which has a primary recognition motif in extracellular matrix, Arg-Gly-Asp (RGD) sequence. Data from inhibition activity assay for the ${\alpha}_v{\beta}_3$ integrin showed that saxatilin showed about 5000-fold higher activity than those of RGD peptides, suggesting that RGD sequence may not be sufficient to induce full cellular function of this site. The solution structures calculated from NMR data were well converged for backbone atoms except RGD loop. The structure revealed that most of tight turns are stabilized by medium range NOE contacts and the RGD motif is located far from the rigid core of the C-terminal domain. The three-dimensional fold and biological function of saxatilin are discussed with those of salmosin, which is a disintegrin protein derived from Agkistrodon halys brevicaudus.

• BMB Reports
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• v.40 no.2
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• pp.290-294
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• 2007

Saxatilin is a disintegrin known to inhibit tumor progression in vivo and in vitro. The role of saxatilin in cancer cell invasion was examined by a modified Boyden chamber assay in MDAH 2774 human ovarian cancer cell line. Saxatilin (50 nM) significantly inhibited cancer cell invasion induced by tumor necrosis factor-$\alpha$ (TNF-a$\alpha$). Saxatilin also reduced MMP-9 mRNA levels in cancer cells in a dosedependent manner. In addition, TNF-$\alpha$-induced MMP-9 activity was reduced by the treatment of saxatilin. These results indicate that transcriptional regulation of MMP-9 is an important mechanism for the tumor suppressive effects of saxatilin in MDAH 2774 human ovarian cancer cells.

• BMB Reports
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• v.40 no.3
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• pp.439-443
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• 2007

Tumor growth and metastasis are dependent on angiogenesis, and endothelial cell invasion and migration are apparent means of regulating tumor progression. We report here that saxatilin, a snake venom-derived disintegrin, suppresses the angiogenesis-inducing properties of NCI-H460 human lung cancer cells. Culture supernatants of NCI-H460 cells are able to induce human umbilical vascular endothelial cell (HUVEC) invasion and tube formation. However, treatment of the cancer cells with saxatilin resulted in reduced angiogenic activity of the culture supernatant. This suppressed angiogenic property was found to be associated with the level of vascular endothelial growth factor (VEGF) in the culture supernatant. Further experimental evidence indicated that saxatilin inhibits VEGF production in NCI-H460 cells by affecting hypoxia induced factor-1$\alpha$ (HIF-1$\alpha$) expression via the Akt pathway.

• Molecules and Cells
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• v.28 no.5
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• pp.441-446
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• 2009

During epididymal transit, mammalian sperm acquire selected proteins secreted by the epididymis. We previously showed that a disintegrin and metalloprotease (ADAM) 7 is expressed specifically in the epididymis and transferred to the sperm surface during epididymal transit. Here, we show that mouse ADAM7 secreted to the epididymal lumen is associated with membranous vesicles known as epididymosomes. Furthermore, we found that ADAM7 can be transferred directly from epididymal vesicles to sperm and that it is an integral plasma membrane protein in sperm. Thus, our study provides new information regarding the unique mode of secretion and interaction of ADAM7 during the epididymis-to-sperm transfer process.

• Molecules and Cells
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• v.19 no.2
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• pp.205-211
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• 2005

The Arg-Gly-Asp (RGD) sequence serves as the primary recognition site in extracellular matrix proteins, and peptides containing this sequence can mimic the biological activities of matrix proteins. We have initiated structure-function studies of two RGD containing peptides, RGD-5(AGGDD) and cyclic RGD-6(CARGDDC). Assays have shown that cyclic RGD-peptides inhibit platelet aggregation more efficiently than linear ones. NMR data revealed that RGD-5 and RGD-6 have entirely different conformation. RGD-5 has a linear extended structure and RGD-6 has a stable loop conformation. In RGD-5 the guanidinium group of Arg2 and the carboxyl group of Asp4 lie in parallel, whereas the side-chains of Arg3 and Asp5 of RGD-6 are located in different planes, supporting the idea that the stability of the cyclic form derives from the packing of the side chain of the Arg and Asp residues. The structural features of these peptides could provide a basis for designing new drugs against diseases related to platelet aggregation and as cancer antagonists.

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2002.01a
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• pp.25-25
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• 2002

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1366-1372
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• 2018

Objective: A disintegrin and metallopeptidase with thrombospondin motifs type 8 (ADAMTS8) is crucial for diverse physiological processes, such as inflammation, tissue morphogenesis, and tumorigenesis. The chicken ADAMTS8 (chADAMTS8) gene was differentially expressed in the kidney following exposure to different calcium concentrations, suggesting a pathological role of this protein in metabolic diseases. We aimed to examine the molecular characteristics of chADAMTS8 and analyze the gene-expression differences in response to toll-like receptor 3 (TLR3) stimulation. Methods: The ADAMTS8 mRNA and amino acid sequences of various species (chicken, duck, cow, mouse, rat, human, chimpanzee, pig, and horse) were retrieved from the Ensembl database and subjected to bioinformatics analyses. Reverse-transcription polymerase chain reaction (RT-PCR) and quantitative PCR (qPCR) experiments were performed with various chicken tissues and the chicken fibroblast DF-1 cell line, which was stimulated with polyinosinic-polycytidylic acid (poly[I:C]; a TLR3 ligand). Results: The chADAMTS8 gene was predicted to contain three thrombospondin type 1 (TSP1) domains, whose amino acid sequences shared homology among the different species, whereas sequences outside the TSP1 domains (especially the amino-terminal region) were very dif­ferent. Phylogenetic analysis revealed that chADAMTS8 is evolutionarily clustered in the same clade with that of the duck. chADAMTS8 mRNA was broadly expressed in chicken tissues, and the expression was significantly up-regulated in the DF-1 cells in response to poly(I:C) stimulation (p<0.05). These results showed that chADAMTS8 may be a target gene for TLR3 signaling. Conclusion: In this report, the genetic information of chADAMTS8 gene, its expression in chicken tissues, and chicken DF-1 cells under the stimulation of TLR3 were shown. The result suggests that chADAMTS8 expression may be induced by viral infection and correlated with TLR3-mediated signaling pathway. Further study of the function of chADAMTS8 during TLR3-dependent inflammation (which represents RNA viral infection) is needed and it will also be important to examine the molecular mechanisms during different regulation, depending on innate immune receptor activation.

• BMB Reports
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• v.48 no.5
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• pp.277-282
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• 2015

We demonstrated previously that a disintegrin and metalloproteinase 15 (ADAM15) is released into the extracellular space as an exosomal component, and that ADAM15-rich exosomes have tumor suppressive functions. However, the suppressive mechanism of ADAM15-rich exosomes remains unclear. In this study, we show that the ADAM15 ectodomain is cleaved from released exosomes. This shedding process of the ADAM15 ectodomain was dramatically enhanced in conditioned ovarian cancer cell medium. Proteolytic cleavage was completely blocked by phenylmethylsulfonyl fluoride, indicating that a serine protease is responsible for exosomal ADAM15 shedding. Experimental evidence indicates that the ADAM15 ectodomain itself has comparable functions with those of ADAM15-rich exosomes, which effectively inhibit vitronectininduced cancer cell migration and activation of the MEK/extracellular regulated kinase signaling pathway. We present a tumor suppressive mechanism for ADAM15 exosomes and provide insight into the functional significance of exosomes that generate tumor-inhibitory factors. [BMB Reports 2015; 48(5): 277-282]

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.2907-2909
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• 2012

A disintegrin and metalloprotease with thrombospondin domains (ADAMTS) are a member of peptidase and involved in processing of von Willebrand factor as well as cleavage of aggrecan, versican, brevican and neurocan. Among 19 subfamilies of human ADAMTS, ADAMTS-4 is a zinc-binding metalloprotease and is a famous therapeutic target for arthritis. It has been reported that a flavonoid luteolin shows inhibitory activity against ADMATS-4. In this study, we verified that luteolin is a potent inhibitor of ADAMTS-4 and probed the molecular basis of its action. On the basis of a docking study, we proposed a binding model between luteolin and ADAMTS-4 in which 3',4'-dihydroxyl groups in luteolin formed hydrogen bonding with ADMATS-4 and these interactions are important for its inhibitory activity against ADAMTS-4.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.4
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• pp.318-321
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• 2019

Recent studies showed that tight junctions (TJs) integrity and assembly are required for blastocyst development in mouse and pig models. However, the biological functions of TJs associated with embryo implantation and maintenance of pregnancy were not investigated yet. To examine whether disrupted TJs affect further embryo development, we employed RNAi approach and inhibitor treatment. The embryos were injected with Cxadr (Coxsackievirus and adenovirus receptor) siRNA for knock down (KD) and treated with Adam10 (A Disintegrin and Metalloproteinase specific inhibitor 10; GI254023X; SI). We compared blastocyst development and paracellular sealing assay using FITC dextran uptake between control and KD or SI embryos. Finally, we transferred control and Cxadr KD or Adam 10 SI treated blastocyst to uteri of recipients. Cxadr KD and Adam 10 SI showed lower blastocyst development and more permeable to FITC-dextran. Moreover, we observed that half of KD and inhibited embryos failed to maintain pregnancies after the second trimester. Our findings suggested that TJs integrity is required for the maintenance of pregnancy and can be used as a selective marker for the successful application of assisted reproduction technologies.