| 1. |
Shun-ichiro Kawabata, Toshio Shibata, Purification and Assays of Tachylectin-5, Jun Hirabayashi (ed.), Lectin Purification and Analysis: Methods and Protocols, Methods in Molecular Biology, vol. 2132, https://doi.org/10.1007/978-1-0716-0430-4, 2020.04, Tachylectin-5, a 41-kDa protein with a common fold of the C-terminal globular domain of the γ-chain of fibrinogen, is purified from horseshoe crab hemolymph plasma by affinity column chromatography, using acetyl-group-immobilized resin. Two types of isolectins, tachylectin-5A and tachylectin-5B, are obtained by stepwise elution with GlcNAc at 25 and 250 mM, respectively. Tachylectins-5A and -5B exhibit extraordinarily strong hemagglutinating activity against all types of human erythrocytes (the minimum agglutinating concentration of 0.004−0.008 μg/mL for tachylectin-5A and 0.077−0.27 μg/mL for tachylectin-5B). Their hemagglutinating activities are inhibited by acetyl group-containing sugars and non-carbohydrates such as sodium acetate, acetylcholine, and acetyl CoA (the minimum inhibitory concentrations of 1.3−1.6 mM), indicating that the acetyl group is required and sufficient for recognition by tachylectins-5A and -5B. EDTA inhibits their hemagglutinating activity, whereas the inhibition is overcome by adding an excess amount of Ca2+. Tachylectins-5A and -5B also exhibit bacterial agglutinating activity against both Gram-negative bacteria (the minimum agglutinating concentrations of 0.04−0.08 μg/mL for tachylectin-5A and 0.05−0.11 μg/mL for tachylectin-5B) and Gram-positive bacteria (the minimum agglutinating concentrations of 0.3−2.4 μg/mL for tachylectin-5A and 15.1−26.8 μg/mL for tachylectin-5B). Interestingly, tachylectins-5A and -5B enhance the antimicrobial activity of a hemocyte-derived peptide, big defensin.. |
| 2. |
Shun-ichiro Kawabata, Toshio Shibata, Purification and Assays of Tachylectin-2, 2020.06, Tachylectin-2, a 27-kDa protein consisting of a five-bladed β-propeller structure, is purified by three steps of chromatography, including dextran sulfate-Sepharose CL-6B, CM-Sepharose CL-6B, Mono S. Three isolectins of tachylectin-2 including tachylectin-2a, -2b and -2c are purified. These isolectins exhibit hemagglutinating activity against human A-type erythrocytes in a Ca2+-independent manner with tachylectin-2b showing the highest activity. Tachylectin-2b specifically agglutinates Staphylococcus saprophyticus KD. The tachylectin-2b-medatred hemagglutination is inhibited in the presence of GlcNAc and GalNAc. The association constants for GlcNAc and GalNAc are Ka = 1.95 × 104 M-1 and Ka = 1.11 × 103 M-1, respectively. Ultracentrifugation analysis shows that tachylectin-2b is present in monomer form in solution. |
| 3. |
Shun-ichiro Kawabata, Toshio Shibata, Purification and Assays of Tachycitin, 2020.04, An antimicrobial peptide tachycitin (73 amino acids) is purified by steps of chromatography, including
Sephadex G-50 and S Sepharose FF, from the acid extract of hemocyte debris of horseshoe crabs. Tachycitin
is present in monomer form in solution, revealed by ultracentrifugation analysis. Tachycitin exhibits
bacterial agglutination activity and inhibits the growth of both Gram-negative bacteria, Gram-positive
bacteria, and fungus Candida albicans. Interestingly, tachycitin shows synergistic antimicrobial activity in
corporation with another antimicrobial peptide, big defensin. Tachycitin shows a specific binding activity to
chitin but not to cellulose, mannan, xylan, and laminarin. Tachycitin is composed of the N-terminal threestranded
β-sheet and the C-terminal two-stranded β-sheet following a short helical turn, and the C-terminal
structural motif shares a significant structural similarity with the chitin-binding domain derived from a plant
chitin-binding protein, hevein.. |
| 4. |
Shibata, T. and Kawabata, S., Pluripotency and a secretion mechanism of Drosophila Transglutaminase., Journal of Biochemistry, 10.1093/jb/mvx059, 2018.05. |
| 5. |
Shibata, T. and Kawabata, S., Pluripotency and a secretion mechanism of Drosophila Transglutaminase., 2018.03. |
| 6. |
Shun-ichiro Kawabata, Transglutaminase in Invertebrates., In Transglutaminases: multiple functional modifier and targets for new drug discovery (Hitomi, K., Kojima, S., and Fesus, L. Eds.) (2015), pp 117-127, Springer, Tokyo, Heidelberg, New York, and London., 2016.06. |
| 7. |
Cerenius, L., Kawabata, S., Lee. B. L., Nonaka, M., and Söderhäll, K., Proteolytic cascades and their involvement in invertebrate immunity., Trends in Biochemical Sciences, 2010.07. |
| 8. |
Kawabata, S., Immunocompetent molecules and their response network in horseshoe crabs. In Invertebrate Immunity , 2010.07. |
| 9. |
Kawabata, S. and Muta, T., JB Reflections and Perspectives. Sadaaki Iwanaga: discovery of the lipopolysaccharide- and β-1,3-D-glucan-mediated proteolytic cascade and unique proteins in invertebrate immunity., Journal of Biochemistry, 2010.06. |
| 10. |
Shun-ichiro Kawabata, Takumi Koshiba, Toshio Shibata, The lipopolysaccharide-activated innate immune response network of the horseshoe crab, Invertebrate Survival Journal, 2009.05. |
| 11. |
Shoichiro Kurata, Shigeru Ariki and Shun-ichiro Kawabata, Recognitiion of pathogens and activation of immune responses in Drosophila and horseshoe crab innate immunity, Elsevier, 2006.01. |
| 12. |
Kei-ichiro Inamori, Shigeru Ariki, Shun-ichiro Kawabata, A toll-like receptor in horseshoe crabs, Blacwell, 2004.01. |
