Bilusich Daniel, Jackway Rebecca J, Musgrave Ian F, Tyler Michael J, Bowie John H
Department of Chemistry, The University of Adelaide, South Australia, 5005 Australia.
Rapid Commun Mass Spectrom. 2009 Sep;23(17):2628-36. doi: 10.1002/rcm.4164.
Positive and negative ion electrospray mass spectrometry together with Edman sequencing (when appropriate) has been used to sequence the host-defence peptides secreted from skin glands of the tree frog Litoria peronii. The peptide profiles are different in winter and summer. In winter, the frog produces small amounts of the known caerin 1.1 [GLLSVLGSVAKHVLPHVVPVIAEHL-NH(2)] (a wide-spectrum antibiotic) and caerin 2.1 [GLVSSIGRALGGLLADVVKSKQPA-OH], a narrow-spectrum antibiotic and an inhibitor of neuronal nitric oxide synthase. The major peptides produced throughout the year are the pGlu-containing peroniins 1.1 to 1.5 (e.g. peroniin 1.1 [pEPWLPFG-NH(2)], a smooth muscle contractor from 10(-7) M), and caerulein [pEQDY(SO(3)H)TGWMDF-NH(2)], a known and potent smooth muscle contractor from 10(-10) M. There are also some precursors to the peroniin 1 peptides, only detected in the skin secretion in summer, which are inactive and appear to be all (or part) of the spacer peroniin 1 peptides, e.g. peroniin 1.1b [SEEEKRQPWLPFG-NH(2)]. There are three members of the Litoria peronii Group of tree frogs classified in Australia, namely, L. peronii, L. rothii and L.tyleri. A comparison of the skin peptide profiles of L. peronii with those reported previously for L. rothii suggests that either these two species of tree frog are not as closely related as determined previously on morphological grounds, or that skin peptide divergence in tree frogs of this Group is more extensive than in others that have been studied.
正离子和负离子电喷雾质谱联用（适当时）埃德曼测序法，已用于对斑腿树蛙（Litoria peronii）皮肤腺分泌的宿主防御肽进行测序。肽谱在冬季和夏季有所不同。冬季，这种青蛙会产生少量已知的caerin 1.1 [GLLSVLGSVAKHVLPHVVPVIAEHL-NH₂]（一种广谱抗生素）和caerin 2.1 [GLVSSIGRALGGLLADVVKSKQPA-OH]，一种窄谱抗生素和神经元型一氧化氮合酶的抑制剂。全年产生的主要肽类是含焦谷氨酸的peroniins 1.1至1.5（例如peroniin 1.1 [pEPWLPFG-NH₂]，一种从10⁻⁷ M起作用的平滑肌收缩剂），以及蛙皮素[pEQDY(SO₃H)TGWMDF-NH₂]，一种从10⁻¹⁰ M起作用的已知强效平滑肌收缩剂。还有一些peroniin 1肽的前体，仅在夏季的皮肤分泌物中检测到，它们没有活性，似乎是间隔peroniin 1肽的全部（或部分），例如peroniin 1.1b [SEEEKRQPWLPFG-NH₂]。在澳大利亚，斑腿树蛙组有三种树蛙，即斑腿树蛙（L. peronii）、罗氏树蛙（L. rothii）和泰勒树蛙（L.tyleri）。将斑腿树蛙的皮肤肽谱与先前报道的罗氏树蛙的肽谱进行比较表明，要么这两种树蛙的亲缘关系不像之前根据形态学确定的那样密切，要么该组树蛙的皮肤肽差异比其他已研究的树蛙更广泛。
