• Journal of the Korean Institute of Landscape Architecture International Edition
• /
• 제1호
• /
• pp.75-83
• /
• 2001

Residents of urban area like to be near rural animals during their daily life, so it is important conserve the suburban Yato landscape in Japan. This study targets the species of frogs that are commonly found in Yato paddies. It is necessary to various frogs inhabiting in Yato, because frogs are popular among Japanese, who as children enjoy capturing tadpoles and frogs. Its purpose is to clarify how that composition of frog species changes when the functionality of a frog habitat is diminished by urbanization. The survey, conducted in the Eastern Kanagawa area in central Japan, determined the distribution of each species of frog in grid cells measuring 0.5-$\textrm{km}^2$. It hsows wide distributing species (Hyla japonica; they always inhabit in all paddies), the middle range distributing species (Rhacophorus schlegelii and Rana porosa p.), the limited range distributing species (R. rugosa; they are most critical species, sine they are recognized only two cells), and so on. Correspondence analysis based on the frog species composition in each cell was performed to ascertain the adaptability of each species to various paddy field conditions. The results allowed us to classify cells into four groups according to the composition of the inhabiting species. And we recognized that the process by which frogs disappear occurs in reaction to either of two patterns of change. As paddy fields are improved by farmland consolidation, R. rugosa, R. ornativentris, R. japonica, and Bufo. japonica f. decline rapidly. In plateau areas, a smore andmore paddies are converted into strong, well-drained fields, only H. japonica and R. porosa p. remain. But in hilly areasd, the species composition becomes only H. japonica and R. schlegelii. Finally, we discuss the concept of ecological urban design in the context of the conservation of frog species in Yato paddies.

• BMB Reports
• /
• 제40권2호
• /
• pp.261-269
• /
• 2007

The structure and dynamics of a 37-residue antimicrobial peptide gaegurin 4 (GGN4) isolated from the skin of the native Korean frog, Rana rugosa, was determined in SDS micelles by NMR spectroscopy. The solution structure of the peptide in SDS micelles was determined from 352 NOE-derived distance constraints and 22 backbone torsion angle constraints. Dynamic properties for the amide backbone were characterized by $^1H-^{15}N $heteronuclear NOE experiments. The structural study revealed two amphipathic helices spanning residues 2-10 and 16-32 and that the helices were connected by a flexible loop. An intraresidue disulfide bridge was formed between residues Cys31 and Cys37 near the C-terminus. The loop region (11-15) connecting the two helices are were slightly more flexible than these helices themselves. From the fact that since there is no contact NOEs between two helices, it is implied that the GGN4 peptide shows an independent motion of both helices which has an angle of about $ 60^{\circ}-120^{\circ}$ from each other.

• BMB Reports
• /
• 제32권1호
• /
• pp.12-19
• /
• 1999

Gaegurin 4 (GGN4), a broad-spectrum antibiotic, is a 37-amino acid peptide isolated from the Korean frog, Rana rugosa. In this study, we have chemically synthesized and purified GGN4 analogues where the C-terminal portion is truncated and/or substituted with tryptophan. These peptides show significantly different biological activities depending on the location of tryptophan and the number of amino acids truncated from the C-terminal end. While deletion of 9 amino acids from the C-terminal seems to be marginally tolerable in maintaining the antimicrobial activity, further deletion of up to 14 amino acid residues decreases the potency by more than 60-fold towards Gram-positive, and 10-fold towards Gram-negative, bacteria. Surprisingly, the reduced activity of the shorter peptide can be completely restored by a single substitution of aspartic acid 16 to tryptophan 16 (D16W). Also, the truncation seems to decrease the specificity of antibiotic activity more towards Gram-positive than towards Gram-negative bacteria studied. These data suggest a partial role of the C-terminal region in determining the binding specificity and the activity of peptides upon binding to their target cell membranes.

• Molecules and Cells
• /
• 제21권2호
• /
• pp.229-236
• /
• 2006

Gaegurin 4 (GGN4), a novel peptide isolated from the skin of a Korean frog, Rana rugosa, has broad spectrum antimicrobial activity. A number of amphipathic peptides closely related to GGN4 undergo a coil to helix transition with concomitant oligomerization in lipid membranes or membrane-mimicking environments. Despite intensive study of their secondary structures, the oligomeric states of the peptides before and after the transition are not well understood. To clarify the structural basis of its antibiotic action, we used analytical ultracentrifugation to define the aggregation state of GGN4 in water, ethyl alcohol, and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). The maximum size of GGN4 in 15% HFIP corresponded to a decamer, whereas it was monomeric in buffer. The oligomeric transition is accompanied by a cooperative 9 nm blue-shift of maximum fluorescence emission and a large secondary structure change from an almost random coil to an ${\alpha}$-helical structure. GGN4 induces pores in lipid membranes and, using electrophysiological methods, we estimated the diameter of the pores to be exceed $7.3{\AA}$, which suggests that the minimal oligomer structure responsible is a pentamer.

• 한국습지학회지
• /
• 제18권2호
• /
• pp.113-120
• /
• 2016

본 연구는 민간인통제구역에 건설된 제방으로 인한 생태계 분절이 양서류 서식지에 미치는 영향을 알아보기 위해 수행되었다. 이를 위해 제방 한편에 두 논(사이트 1, 2)과 제방 옆을 지나는 수내천(사이트 3), 그리고 제방 다른 편의 관개수로가 위치한 논(사이트 4)에 대해 7개월간에 걸쳐 조사를 실시하였다. 조사 결과, 주로 논과 수변지역에 많이 서식하는 참개구리(295개체), 청구개리(n=220개체), 옴개구리(124개체)가 주로 발견되었고 한국산 개구리(8개체)와 두꺼비(3개체)도 일부 확인되었다. 이 양서류들은 계절에 따른 물 공급 상황의 변화에 따라 논과 하천 지역에서 양적 변화를 보여 사이트 1,2,3에서 두드러지게 나타났으나 제방 반대편의 사이트 4에서는 풍부한 수자원에도 불구하고 양적 변화가 적은 것으로 나타났다. 가뭄철 수내천에 물이 말라 이 지역 개구리들이 현저히 감소했을 때에도 물이 풍부하고 거리가 비슷한 제방 건너편의 사이트 4보다는 제방 같은 편의 사이트 1, 2 지역에서 다수의 개구리들의 존재가 확인되었다.