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ABSTRACT:   Until now, six crustacean hyperglycemic hormones (CHH) designated Pej-SGP-I, -II, -III, -V, -VI and -VII have been characterized in the kuruma prawn Penaeus japonicus . All CHH consist of 72 amino acid residues and have an amidated carboxyl (C)-terminus. In the present study, we expressed Pej-SGP-III in methylotrophic yeast Pichia pastoris in order to obtain a large quantity of recombinant CHH possessing biological activity. A cDNA encoding Pej-SGP-III that had been previously cloned was processed by polymerase chain reaction (PCR) and the resulting product was ligated into an expression vector. Pichia pastoris was transformed with this vector after which a recombinant Pej-SGP-III was expressed having an additional amino acid residue (glycine) at the C-terminus (rPej-SGP-III-Gly), a form considered to be a putative precursor of this hormone. rPej-SGP-III-Gly secreted into the culture medium was purified by reversed-phase HPLC, and amidated using a peptidylglycine alpha-amidating enzyme. The amidated rPej-SGP-III (rPej-SGP-III) showed hyperglycemic activity in in vivo bioassay almost comparable to that of the natural Pej-SGP-III. rPej-SGP-III thus obtained will be a useful tool not only for its physiological study but also for the determination of its 3-D structure.  相似文献   
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ABSTRACT:   The nucleotide sequences of Japanese flounder Paralichthys olivaceus , major histocompatibility complex (MHC) cDNA, classical MHC class Iα, non-classical MHC class Iβ, MHC class IIα and IIβ, were determined. The domain structures and antigen binding motifs of vertebrate MHC are conserved in the Japanese flounder MHC. A phylogenetic analysis supports the classification of these genes into class I and class II MHC. Classical MHC class Iα was ubiquitously expressed, whereas the non-classical MHC class Iβ was expressed mainly in lymphoid organs, gills, intestine and stomach. The MHC classes IIα and IIβ were also ubiquitously expressed.  相似文献   
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ABSTRACT:   Antimicrobial peptides serve as an important component of the innate immune system of all species by functioning to provide a rapid first line defense against infection. Arthropod antimicrobial peptides have been well described in insects, whereas only a few molecules have been identified in crustaceans. Five variants (types 1–5) of Marsupenaeus japonicus crustin-like peptide cDNA that were obtained from a hemocyte cDNA library and polymerase chain reaction (PCR) amplification are reported here. Marsupenaeus japonicus crustin-like peptide type 1, the predominant type, has a cDNA consisting of 679 nucleotides and an open reading frame consisting of 573 base pairs coding for 191 amino acid residues. Other types contain varying glycine-rich repeats at the N-terminal amino acid sequences. The deduced amino acid sequences of these variants are highly similar to those of Litopenaeus setiferus (80% identity), Litopenaeus vannamei (80% identity) and Carcinus maenas crustins (44% identity). Expression of Marsupenaeus japonicus crustin-like peptide mRNA was detected in hemocytes, but not in the heart, hepatopancreas, gill, fore-gut, mid-gut, muscle, subcuticular epithelium or ovary. The expression level of crustin-like peptide mRNA increased significantly 1, 3 and 7 days post-peptidoglycan feeding as determined by quantitative real-time PCR. These results suggest that crustin-like peptide could have an important role in shrimp defense mechanisms.  相似文献   
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通过热水蒸煮法测得高产脂马尾松的枝条精油含量高于普通马尾松,而针叶精油含量,两种类型的马尾松无大的差别;枝条精油含量较针叶低.气相色谱分析表明:两种类型的马尾松的精油在组成成份上无大的差别,枝、叶相比,枝条精油的构成成份少.生物检定表明:两种类型的马尾松精油对紫花苜蓿的种子的发芽及幼苗的生长都具有一定的影响,并存在一定的差别。用四种不同极性的溶剂(正己烷、苯、乙醚、甲醇)对枝、叶进行逐次抽出,其中甲醇的抽出物含量最高,针叶的抽出物含量高干枝条的抽出物含量。  相似文献   
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Volatile organic chemicals (VOCs) are emitted as gases from certain solids or liquids, which include a variety of chemicals, some of them may have short- and long- term adverse health effects. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. VOCs are emitted by a wide array of products numbering in the thousands, for example: paints and lacquers, paint strippers, cleaning supplies, pesticides, building materials and furnishings, office equi…  相似文献   
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