caa a22 4500 397494335 CHVBK 20180308164517.0 cr unu---uuuuu 161202e199505 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a124818 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a124818 A Novel Big Defensin Identified in Horseshoe Crab Hemocytes: Isolation, Amino Acid Sequence, and Antibacterial Activity [Elektronische Daten] [Tetsu Saito, Shun-ichiro Kawabata, Takeshi Shigenaga, Yoko Takayenoki, Junko Cho, Hiroshi Nakajima, Michimasa Hirata, Sadaaki Iwanaga] Hemocytes of the horseshoe crab (limulus) contain a family of arthropodous peptide antibiotics, termed the tachyplesin family, and antibacterial protein, called anti-LPS factor, of which the former is located in the small (S) granules and the latter in the large (L) granules of the hemocytes. In our ongoing studies on granular components, we have identified here a novel defensin-like substance present in both L- and S-granules. This substance strongly inhibits the growth of Gram-negative and -positive bacteria, and fungi, such as Candida albicans. The isolated substance, tentatively termed "big defensin,” consists of 79 amino acid residues, of which the COOH-terminal 37 residues have a sequence similar to those of mammalian neutrophil-derived defensins, especially rat defensin. Characterization of the disulfide motif in big defensin indicated that the disulfide array is identical to that of β-defensins from bovine neutrophils. One clear structural difference is that the limulus hemocyte-derived big defensin has an extension of the NH2-terminal hydrophobic sequence with 35 amino acid residues followed by the COOH-terminal cationic defensin portion. This amphipathic nature of big defensin seems likely to be associated with its potent antibacterial activity. Furthermore, antibacterial activities of the NH2-terminal hydrophobic region and the COOH-terminal defensin portion separated by tryptic digestion are significantly different: the former displays a more potent activity against Gram-positive bacteria, whereas the latter is more potent against Gram-negative bacteria. Big defensin, therefore, may prove to represent a new class of defensin family possessing two functional domains with different antimicrobial activities. © Oxford University Press Regular Papers nationallicence antibacterial activity nationallicence big defensin nationallicence hemocytes nationallicence horseshoe crab nationallicence primary structure nationallicence Saito Tetsu Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut Kawabata Shun-ichiro Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut Shigenaga Takeshi Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut Takayenoki Yoko Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut Cho Junko Department of Biology, Faculty of Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut Nakajima Hiroshi Central Research Institute, Taiyo Fishery Co. Tsukuba, Ibaraki 300-42 aut Hirata Michimasa Department of Bacteriology, School of Medicine, Iwate Medical University Morioka, Iwate 020 aut Iwanaga Sadaaki Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut The Journal of Biochemistry Oxford University Press 117/5(1995-05), 1131-1137 0021-924X 117:5<1131 1995 117 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a124818 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a124818 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Saito Tetsu Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut NATIONALLICENCE 700 1- Kawabata Shun-ichiro Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut NATIONALLICENCE 700 1- Shigenaga Takeshi Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut NATIONALLICENCE 700 1- Takayenoki Yoko Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut NATIONALLICENCE 700 1- Cho Junko Department of Biology, Faculty of Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut NATIONALLICENCE 700 1- Nakajima Hiroshi Central Research Institute, Taiyo Fishery Co. Tsukuba, Ibaraki 300-42 aut NATIONALLICENCE 700 1- Hirata Michimasa Department of Bacteriology, School of Medicine, Iwate Medical University Morioka, Iwate 020 aut NATIONALLICENCE 700 1- Iwanaga Sadaaki Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33 Higashi-ku, Fukuoka 812 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 117/5(1995-05), 1131-1137 0021-924X 117:5<1131 1995 117 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford