572 resultados para lectin


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分离提取海洋无脊椎动物贻贝(Crenomytilus grayanus)凝集素,考察其抗HIV活性。采用半乳糖-Sepharose 6B亲和层析和Sephacryl S-200层析分离提取贻贝凝集素(Crenomytilus grayanus lectin,CGL),以光镜检查合胞体抑制试验,以ELSA测定HIVp24抗原表达水平。从海洋无脊椎动物贻贝中分离出的凝集素(CGL),为N-乙酰半乳糖胺/半乳糖(GalNAc/Gal)特异性的凝集素。CGL在27.88mg.L-1浓度时,对HIV诱导细胞病变的抑制达50%;在45.70mg.L-1时,对HIV-1复制的抑制达50%;同时在35.12mg.L-1浓度时,对HIV感染细胞融合的阻断达50%。

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银鲫卵母细胞特异的凝集素(Gibel carp oocyte-specific lectin,GOL)是经差减杂交筛选出来的。本研究采用原核表达方法,利用Pinpoint-T载体表达了该凝集素的部分肽段(从22到214个氨基酸),并经纯化用来免疫家兔制备多克隆抗体。采用免疫荧光共定位方法,证明该凝集素是卵母细胞中皮质颗粒的成分之一。

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The cDNA encoding grass carp intelectin was isolated from a head kidney cDNA library, and termed gcIntL. The deduced amino acid sequence of gcIntL consists of 318 amino acids, and about 55% identical and 74% similar to human intelectin, which is a new type of lectin recognizing galactofuranose, and plays a role in the recognition of bacteria-specific components in animal hosts. The gcIntL gene consists of seven exons and six introns, spacing over approximately 3 kb of genomic sequence. Phylogenetic analysis clearly demonstrated that the gcIntL formed a clade with Danio rerio intelectin and 35 kDa serum lectin. By real-time quantitative RT-PCR analysis, gcIntL transcripts were significantly induced in head kidney, trunk kidney, spleen, and intestine from LPS-stimulated fish. RT-PCR and Western blotting analysis demonstrated that the mRNA and protein of gcIntL gene have the same expression pattern, and both were detected in brain, gill, intestine, head kidney, trunk kidney, spleen, and heart. Furthermore, gcIntL protein could be detected in gill, intestine, trunk kidney, head kidney, spleen, heart, and brain including medulla oblongata and optic lobe, as determined by immunohistochemistry. This is the first report of intelectin expression pattern in fish, and of recombinant gcIntL and polyclonal antibody against gcIntL. (c) 2006 Elsevier Ltd. All rights reserved.

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本论文研究了从圆斑蛙蛇泰国亚种(Daboia russellii siamensis)蛇毒中纯化的C一型凝集素样蛋白Dabocetin和L一氨基酸氧化酶DRS一AO的理化性质、生物学活性和分子克隆。Dabocetin是分子量约为28扔。的异二聚体蛋白,它由分子量约为15.0kDa和14.5kDa的两个同源亚基以和p共价结合形成。N-末端氨基酸序列比较显示,Dabocetin与目前已知的蛇毒c一型凝集素样蛋白有很高的同源性。即使在终浓度达50.0。叫而时,Dabocetin也不能直接诱导血小板聚集。此外,在终浓度为40.00μg/ml时,Dabocetin几乎不能抑制由AdP,TMVA和stejnulxin诱导的血小板聚集。但是,Dabocetin呈剂量依赖地抑制瑞斯托霉素诱导的血小板凝集,其半数抑制率ICS。值为10.80ug/ml。流式细胞仪分析表明,Dabocetin显著抑制单克隆抗体522与GPIba的结合,提示Dabocetin很可能是一个GPIb结合蛋白。从圆斑蛙蛇的毒腺中克隆到了7个编码不同蛇毒C一型凝集素样蛋白亚基的七DNA(命名为DRs一1至DRs一7)。其中,DRsLS编码Dabocetin的a亚基,DRS一6编码Dabocetin的p亚基。DRs一1和DRS一2很可能是圆斑蛙蛇毒腺中表达的X因子激活剂的两条轻链LCZ和LCI的山NA。DRS一3,DRS毛4和DRSL7可能是圆斑蛙蛇毒腺中表达的C一型凝集素样蛋白p亚基的。NA。DRsLAO是一个新的L一氨基酸氧化酶,比活力为1.98U加噶。十二烷基磺酸钠一聚丙烯酞氨凝胶电泳(SDs-PAGE)分析显示,该酶在还原和非还原条件下均呈现一条蛋白带,表观分子量约为58kDa。N-末端氨基酸序列比较显示,DRS一AO与目前已知的蛇毒L一氨基酸氧化酶有很高的同源性。该酶的最适底物为L一亮氨酸,最适pH为8.8。DRs一Ao呈剂量依赖地抑制扔P和仆IvA诱导的血小板聚集,其半数抑制率ICS。值分别为32.8μg/ml和32.3μg/ml。DRS-LAO对金黄色葡萄球菌(灯Cc25923)和耐甲氧西林金黄色葡萄球菌有较强的抗菌作用。DRs一AO对金黄色葡萄球菌必Tcc25923)的最低抑菌浓度卿C)和最低杀菌浓度耐甲氧西林金黄色葡萄球菌的孤CS。和呱Cg。值分别为18.。林留时和36.0μg/ml;DRSLAo对耐甲氧西林金黄色葡萄球菌的MBC50和MBCg。值分别为36.0μg/ml和72.0μg/ml。通过对DRS一AO的分子克隆,得到了编码DRS-AO的部分cDNA序列。

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蛇毒C一型凝集素样蛋白一般是由两个相似亚基组成的异构二聚体或由多个异构二聚体组成的多聚体。烙铁头蛇毒血小板活化素TMVA是一个高分子量的C一型凝集素样蛋白。本文研究了烙铁头蛇毒C一型凝聚素样蛋白的生物活性及其作用机制。同时还从烙铁头蛇毒中分离到一个抗凝蛋白(mucroqucetin)。TMVA呈量效关系地诱导P好和洗涤血小板聚集,提示其活化血小板并不调节v从下或不依赖于vWF。抗人血小板糖蛋白(GP)Ib单克隆抗体HIPI呈剂量依赖性特异性抑制TMVA诱导的血小板聚集。抗人GPllb单克隆抗体PZ也抑制血小板聚集。单克隆抗体和流式细胞术分析显示,FITC一TMVA特异性地、剂量依赖性地结合到福尔马林固定的人血小板上,在FIIC-TMVA4O砚浓度时达到饱和性结合状态,这种结合被HIPI特异性地抑制,并呈剂量依赖性。TMVA不结合血小板GPIX、GPllb、GPllla、GPIa、GPlla和GPIV。Mocarhagin仅能部分阻断TMVA诱导的血小板聚集,然而TMVA却能诱导mocarhagin阻断的血小板聚集。以上结果显示TMVA在GPIbQ上的主要受体位于富含亮氨酸第二次重复区氨基酸残基59一81,除此之外,TMVA可能还有其他结合位点。小鼠体内首次给予TMVA后,在短时间内(15min-30min)引起循环血小板数及网织血小板百分率暂时性减低、血小板膜表面P-seleetin的表达暂时性增加,但循环血液中血小板一白细胞复合物未增加;抗鼠血小板单克隆抗体P一selectin、GPllb、GPlll。免疫组化染色显示脾和肺的组织巨噬细胞呈阴性反应,提示TMVA导致循环血小板减少不是巨噬细胞系统对血小板的清除所致。可能是由于TMVA.通过GPIb活化血小板后使P-selectin暴露于胞浆膜表面,这些脱颗粒的血小板在补体的参与下自身溶破,而导致快速的暂时性血小板减少。给予TMVA.后组织病理学显示,肝、脾、肺、肾、胰、大肠及小肠血管未血栓形成;TMVA不影响内源性和外源性凝血系统;TMVA呈剂量依赖性延长小鼠的出血时间,但在TMvA25p眺g时小鼠的出血时间未延长、仍小于5分钟,是一个安全的剂量。以上结果充分证明TMVA具有体内抗血栓作用,血小板自身溶破导致血小板减少在体内抗血栓中可能也起到重要的作用。体内外实验显示TMVA在动物体内外都具有抗补体活性作用。TMVA上调血小板上DAF和CD59的表达,不同程度地上调白细胞上D胚和CDS夕的表达。TMVA在补体系统中的作用可能与其在异种器宫移植中抗IIAR的发生相关。Mucroqucetin是一个由Q链和p链组成的异二聚体蛋白质,其分子量为25KD。。N一末端氨基酸序列与其它该类蛇毒C一型凝集素样蛋白有很高的同源性。Mucroqucetin呈量效关系延长部分凝血活酶时间(APTT),几乎不影响凝血酶原时间(PT)。因子IX和X的抑制试验显示,该纯化蛋白呈量效关系抑制工X因子的凝血活性,不影响X因子,提示mucroqucetin的抗凝活性主要通过结合FIX而实现,是一个血液凝固IX因子结合蛋白。

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<正>选择素(selectin)与其配体间相互作用介导的细胞粘附在炎症级联反应、肿瘤转移和淋巴细胞归巢等病理、生理过程中起重要作用。其结构组成从远离细胞表面的N-末端到胞内C-末端,依次为:钙型凝集素功能区(Calcium-type lectin domain,Lec),类上皮生长因子功能区(Epidermal Growth Factor-like module,EGF),具有粘附补体蛋白作用的多个重复序列(Consensus Repeats,CRs),跨膜区(Transmembrane,TM)和胞内区

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In order to develop a novel high-throughput tool for monitoring carbohydrate-protein interactions, we prepared carbohydrate or glycoprotein microarrays by immobilizing amino modified carbohydrates on aldehyde-derivatized glass slides or glycoprotein on epoxide-derivatized glass slides and carried out lectin binding experiments by using these microarrays, respectively. The interaction events are marked by attachment of gold nanoparticles followed by silver deposition for signal enhancement. The attachment of the gold nanoparticles is achieved by standard avidin-biotin chemistry.

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Hypoxia, as one suboptimal environmental condition, can affect the physiological state of shrimp during pond aquaculture. To better understand the mechanism of response to hypoxic stress in Chinese shrimp Fenneropenaeus chinensis, proteome research approach was utilized. Differentially expressed proteins of hepatopancreas in adult Chinese shrimp between the control and hypoxia-stressed groups were screened. By 2-DE analysis, 67 spots showed obvious changes after hypoxia. Using LC-ESI-MS/MS, 51 spots representing 33 proteins were identified including preamylase, arginine kinase, phosphopyruvate hydratase, citrate synthase, ATP synthase alpha subunit, chymotrypsin BI, chitinase, ferritin, C-type lectin receptors, transketolase, formylglutathione hydrolase, formyltetrahydrofolate dehydrogenase, aldehyde dehydrogenase, glutathione peroxidase, cytosolic manganese superoxide dismutase, protein disulfide isomerase, beta-actin, oncoprotem nm23, crustacyanin-Cl and so on. These proteins could be functionally classified into several groups such as proteins related to energy production, metabolism-related proteins, immune-related proteins, antioxidant proteins, chaperones, cytoskeleton proteins and ungrouped proteins. The transcription levels of ten selected genes encode the identified proteins were analyzed by real-time PCR at different sampling times of hypoxia. This study is the first analysis of differentially expressed proteins in the hepatopancreas of shrimp after hypoxia and provides a new insight for further study in hypoxic stress response of shrimp at the protein level.

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The family of fibrinogen-related proteins (FREPs) is a group of proteins with fibrinogen-like domains. Many members of this family play important roles as pattern recognition receptors in innate immune responses. The cDNA of bay scallop Argopecten irradians FREP (designated as AiFREP) was cloned by rapid amplification of cDNA ends (RACE) method based on the expressed sequence tag (EST). The full-length cDNA of AiFREP was of 990 bp. The open reading frame encoded a polypeptide of 251 amino acids, including a signal sequence and a 213 amino acids fibrinogen-like domain. The fibrinogen-like domain of AiFREP was highly similar to those of mammalian ficolins and other FREPs. The temporal expression of AiFREP mRNA in hemolymph was examined by fluorescent quantitative real-time PCR. The mRNA level of scallops challenged by Listonella anguillarum was significantly up-regulated, peaked to 9.39-fold at 9 h after stimulation, then dropped back to 4.37-fold at 12 h, while there was no significant change in the Micrococcus luteus challenged group in all periods of treatment. The function of AiFREP was investigated by recombination and expression of the cDNA fragment encoding its mature peptide in Escherichia coli Rosetta gami (DE3). The recombinant AiFREP (rAiFREP) agglutinated chicken erythrocytes and human A, B, O-type erythrocytes. The agglutinating activities were calcium-dependent and could be inhibited by acetyl group-containing carbohydrates. rAiFREP also agglutinated Gram-negative bacteria E. coli JM109, L anguillarum and Gram-positive bacteria M. luteus in the presence of calcium ions. These results collectively suggested that AiFREP functions as a pattern recognition receptor in the immune response of bay scallop and contributed to nonself recognition in invertebrates, which would also provide clues for elucidating the evolution of the lectin pathway of the complement system. (C) 2008 Elsevier Ltd. All rights reserved.

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A total of 10446 expressed sequence tags (ESTs) are obtained by a large-scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis. An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.

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Crustacean haemocytes play important roles in the host immune response including recognition, phagocytosis, melanization, cytotoxicity and inter-cellular signal communication. Expressed sequence tags (ESTs) analysis is proved to be an efficient approach not only for gene discovery, but also for gene expression profiles performance. In order to further understand the innate immune system and defense mechanisms of Chinese shrimp at molecular level, complementary DNA library is constructed from the haemocyte tissue of Fenneropenaeus chinensis. A total of 2371 cDNA clones are successfully sequenced and the average sequence length is 460 bp. About 50% are identified as orthologs of known genes from other organisms by BLASTx and BLASTn program. By sequences comparability and analysis, 34 important genes including 177 ESTs are identified that may be involved in defense or immune functions in shrimp based on the known knowledge. These genes are categorized into five categories according to their putative functions in shrimp immune system: 13 genes are different types of antimicrobial peptides (AMP, penaeidin, antilipopolysaccharide factor, etc.), and their proportion is about 3 8%; 11 genes belong to prophenoloxidase system (prophenoloxidase, serine proteinase, serine proteinase inhibitor, etc.), and their proportion is about 32%; five genes have high homology with clotting protein (lectin, transglutaminase, etc), and their proportion is about 15%; three genes may be involved in inter-cell signal communication (peroxinectin, integrin), and their proportion is about 9%; two genes have been identified to be chaperone proteins (Hsc70, thioredoxin peroxidase), and their proportion is about 6%. These EST sequences enrich our understanding of the immune genes of F chinensis and will help farther experimental research into immune factors and improve our knowledge of the immune mechanisms of shrimp. (c) 2007 Elsevier B.V. All rights reserved.

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The C1q-domain-containing (C1qDC) proteins are a family of proteins characterized by a globular C1q (gC1q) domain in their C-terminus. They are involved in various processes of vertebrates and supposed to be an important pattern recognition receptor in innate immunity of invertebrates. In this study, a novel member of C1q-domain-containing protein family was identified from Zhikong scallop Chlamys farreri (designated as CfC1qDC) by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) approaches. The full-length cDNA of CfC1qDC was of 777 bp, consisting of a T-terminal untranslated region (UTR) of 62 bp and a 3' UTR of 178 bp with a polyadenylation signal sequence AATAAA and a poly (A) tail. The CfC1qDC cDNA encoded a polypeptide of 178 amino acids, including a signal peptide and a C1q-domain of 158 amino acids with the theoretical isoelectric point of 5.19 and the predicted molecular weight of 17.2 kDa. The C1q-domain in CfC1qDC exhibited homology with those in sialic acid binding lectin from mollusks and C1qDC proteins from higher vertebrates. The typical 10 beta-strand jelly-roll folding topology structure of C1q-domain and the residues essential for effective packing of the hydrophobic core were well conserved in CfC1qDC. By fluorescent quantitative real-time PCR, mRNA transcripts of CfC1qDC were mainly detected in kidney, mantle, adductor muscle and gill, and also marginally detectable in hemocytes. In the bacterial challenge experiment, after the scallops were challenged by Listonella anguillarum, there was a significant up-regulation in the relative expression level of CfC1qDC and at 6 h post-injection, the mRNA expression reached the maximum level and was 4.55-fold higher than that of control scallops. Similarly, the expression of CfC1qDC mRNA in mixed primary cultures of hemocytes stimulated by lipopolysaccharides (LPS) was up-regulated and reached the maximum level at 6 h post-stimulation, and then dropped back to the original level gradually. In order to investigate its function, the cDNA fragment encoding the mature peptide of CfC1qDC was recombined and expressed in Escherichia coli BL21 (DE3). The recombinant CfC1qDC protein displayed a significantly strong activity to bind LIDS from E. coli, although no obvious antibacterial or agglutinating activity toward Gram-negative bacteria E. coli JM109, L. anguillarum and Gram-positive bacteria Micrococcus luteus was observed. These results suggested that CfC1qDC was absolutely a novel member of the C1qDC protein family and was involved in the recognition of invading microorganisms probably as a pattern recognition molecule in mollusk. (c) 2008 Elsevier Ltd. All rights reserved.

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C-type lectins are a superfamily of carbohydrate-recognition proteins which play crucial roles as pattern recognition receptors (PRRs) in the innate immunity. In this study, the full-length cDNA of a C-type lectin was cloned from scallop Chlamys farreri (designated as Cflec-5) by expression sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) approach The full-length cDNA of Cflec-5 was of 1412 bp. The open reading frame encoded a polypeptide of 153 amino acids, including a signal sequence and a conserved carbohydrate-recognition domain with the EPN motif determining the mannose-binding specificity The deduced amino acid sequence of Cflec-5 showed high similarity to members of C-type lectin superfamily. The quantitative real-time PCR was performed to investigate the tissue distribution of Cflec-5 mRNA and its temporal expression profiles in hemocytes post pathogen-associated molecular patterns (PAMPs) stimulation. In healthy scallops, the Cflec-5 mRNA was mainly detected in gill and mantle, and marginally in other tissues The mRNA expression of Cflec-5 could be significantly induced by lipopolysaccharide (LPS) and glucan stimulation and reached the maximum level at 6 h and 12 h, respectively But its expression level did not change significantly during peptidoglycan (PGN) stimulation The function of Cflec-5 was investigated by recombination and expression of the cDNA fragment encoding its mature peptide in Escherichia coli Rosetta Gami (DE3) The recombinant Cflec-5 agglutinated Pichia pastoris in a calcium-independent way The agglutinating activity could be inhibited by D-mannose. LPS and glucan, but not by D-galactose or PGN. These results collectively suggested that Cflec-5 was involved in the innate Immune response of scallops and might contribute to nonself-recognition through its interaction with various PAMPs (C) 2010 Elsevier Ltd All rights reserved

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栉孔扇贝是我国北方一种重要的贝类养殖品种。自1997年以来爆发的栉孔扇贝大规模死亡,给地区经济造成了重大损失并且已经严重威胁着扇贝养殖业的健康发展。然而,到目前为止,对扇贝免疫防御分子机理的了解还很少,深入研究扇贝免疫应答的分子机制是认识和了解病害发生和实现病害控制的重要途径。本研究采用了EST大规模测序和3’RACE的方法,从栉孔扇贝cDNA文库中克隆到一个凝集素基因CfLec-2,并对功能进行了研究。 CfLec-2 cDNA全长708bp,5’非翻译区(Untranslated Region, UTR)含有59bp,3’非翻译区含有163bp,具有典型的多聚腺苷酸加尾信号序列AATAAA和多聚腺苷酸尾巴,开放阅读框(Open Reading Frame, ORF )含有486bp,编码162个氨基酸残基,该多肽的理论分子量为16.8 kDa,等电点为4.54。利用SignalP分析,发现其信号肽的剪切位置在VEA-QSL之间。经BLASTP比对分析可知,CfLec-2基因编码的蛋白与人的Brevican,Anguilla japonica的C-type lectin-1和C-type lectin-2, Rattus norvegicus的CD23有较高的相似性,其中与Brevican的一致性有37%。Clustal W多序列比对发现该多肽具有标准长型C型凝集素所必须的6个保守半胱氨酸和相对保守的糖识别位点。用SMART(Small Modular Architecture Research Tool)软件分析发现其具有一个保守的糖识别结构域(Carbohydrate-recognition Domain, CRD),氨基酸序列上第49、125、141、149位置上的半胱氨酸参与形成糖识别结构域,而位于N末端的第21和32位上的两个半胱胺酸形成额外的一个二硫键,位于115、116和117上的Glu、Pro、Asp则构成了糖识别位点。 将编码CfLec-2成熟肽段的cDNA序列克隆进pET32a(+)载体中,并在大肠杆菌Rosetta-gami(DE3)中重组表达CfLec-2。重组蛋白利用其具有的His tag纯化并复性后发现CfLec-2可以凝集溶血葡萄球菌,且凝集过程不需要钙离子的参与。并且,CfLec-2对大肠杆菌TOP10F’有微弱的抑菌活性,对溶壁微球菌、溶血葡萄球菌和鳗弧菌则没有抑菌活性。这一结果说明,CfLec-2可能不仅参与对入侵微生物的识别过程,而且可能作为效应分子起到了直接杀灭入侵微生物的作用。 本研究发现CfLec-2具有和以前在栉孔扇贝报道的CFLec-1完全不同的功 能,说明栉孔扇贝利用不同的凝集素来识别不同的病原,同时也暗示栉孔扇贝中可能有更多不同功能的凝集素有待发现。研究结果丰富和发展了海水无脊椎动物免疫学的内容,对进一步了解扇贝固有免疫的机制,实现养殖扇贝疾病防治具有重要参考价值。

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对虾疾病在世界范围内的频频爆发,给地区经济造成了重大损失。然而到目前为止,我们对于对虾免疫系统的分子机制还知之甚少,深入了解其免疫应答过程,包括异物识别,信息传递以及作用方式等是从根本上解决疾病问题的关键之一。本论文从中国明对虾血细胞中分别克隆了一种C型凝集素基因(Fclectin)、参与凝结过程的谷氨酰胺转移酶基因(FcTG)以及参与凝结级联反应和酚氧化酶原激活系统的两种丝氨酸蛋白酶基因(SP-1和SP-2)和两种丝氨酸蛋白酶抑制剂基因(SPI-1和SPI-2),分析了它们的分子结构特征,预测了其可能的作用,并对它们的组织分布及应答不同病原感染的表达变化模式进行了研究。 首次从对虾中克隆了Fclectin基因,比对结果发现该基因属于C型凝集素超家族的成员之一;Northern blot和原位杂交结果显示,Fclectin基因在部分血细胞中呈组成型表达;利用毛细管电泳半定量RT-PCR方法分别研究了细菌和病毒感染后该基因的表达特征,并初步尝试了利用体外培养的原代血细胞系统研究LPS刺激后Fclectin的表达变化。该基因在感染或刺激后表达水平有明显的改变。 利用RACE技术从中国明对虾血细胞中克隆了一个FcTG基因,它与斑节对虾的谷氨酰胺转移酶基因有93%的相似性,可能编码一种具有活性的TG;原位杂交结果FcTG主要在血细胞中表达,在淋巴器官管腔的血细胞中表达尤为丰富,推断该基因可能主要在吞噬细胞中表达;病原的刺激未能使该基因的表达明显改变,但损伤(注射)的刺激会对其表达产生一定影响。 利用本组构建的对虾血液cDNA文库,克隆到了两个不同的丝氨酸蛋白酶基因,命名为SP-1和SP-2。前者为具有假clip结构域的胰蛋白酶样SP类似物(SPH),后者是一个具有完整的clip结构域的SPH,这在对虾中是首次发现。SP-1和SP-2都主要在血细胞中表达,此外SP-1在淋巴器官中的表达水平也很高;细菌的刺激对SP-1的影响不大,但会诱导SP-2表达量的增加,这两个基因的表达模式在病毒刺激后很相似,都出现先上调后下降的过程,可见病毒的感染会导致这两个基因转录的增强。 利用SMART-RACE技术结合对虾血液cDNA文库的利用,从中国明对虾血细胞中克隆到了两种SPI基因,它们分别为kazal-SPI和serpin-SPI,属于两个不同的家族。SPI-1与斑节对虾的SPI有76%的相似性,推断SPI-1可能主要对弹性蛋白酶、枯草杆菌蛋白酶、胰凝乳蛋白酶等有抑制作用;SPI-2为对虾中首次报道的serpin型抑制剂,它与淡水螯虾的serpin有42%的相似性,SPI-2可能主要对胰蛋白酶、酚氧化酶原激活酶、凝血酶和凝结酶有抑制活性。组织分别特征显示这两个抑制剂基因都在鳃、血细胞和淋巴器官中有高水平的表达。细菌的刺激都会导致这两个基因的表达在感染后出现下调,随后又上升至原有水平;病毒感染后,SPI-1和SPI-2的表达变化情况相似,感染后前12h基本没有明显的改变,到了感染的晚期(感染后24h和48h),随着病毒在体内大量复制,这两个基因的表达都急剧下降至接近基因关闭的状态,这可能暗示着与SPI相对应的蛋白酶的活力将很大程度的异常的增加,机体内稳定的免疫系统平衡状态可能已被破坏。