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采用分子克隆技术克隆了黄羽肉鸡胰蛋白酶原(TRY)基因,并运用多种生物信息学软件对TRY蛋白质结构和功能进行了分析和预测,研究TRY在禽类消化过程中的作用.结果表明:黄羽肉鸡TRY基因的开放阅读框全长747 bp,由248个氨基酸残基组成,其中包含15个氨基酸的信号肽(MKFLVLVAFLGVAVA)和10个氨基酸的激活肽(FPISDEDDDK);该蛋白分子质量为26.1 ku,含有信号肽,不含有糖基化位点,有11个磷酸化位点;此外,该蛋白属于疏水性蛋白,但不存在跨膜区.氨基酸序列比对的结果表明:黄羽肉鸡TRY具有丝氨酸蛋白酶的保守结构特征,如含有催化三联体氨基酸(组氨酸-64、天冬氨酸-110和丝氨酸-203);具有构成6个二硫键所需的12个半胱氨酸残基等.序列一致性分析表明,黄羽肉鸡TRY与纯种鸡的同源性最高,达98.8%.  相似文献   
2.
陈文波  李卫国  赵亚军 《水产学报》2010,34(11):1664-1672
为深入研究胰蛋白酶在鱼类中的生理功能和作用机制,利用生物信息学的方法,成功获得了鲤3种胰凝乳蛋白酶原cDNA序列(ccTRP1、ccTRP2和ccTRP3)并对其进行了序列分析。结果表明,三者均含有一个长度为729bp的开放阅读框(open reading frame,ORF),编码由242个氨基酸组成的胰蛋白酶原,其中包括15个氨基酸组成的信号肽和5个氨基酸(LDDDK)组成的激活肽。总平均亲水性GRAVY(grand average of hydropathicity)分析表明,三者均是亲水性蛋白。氨基酸比对结果显示,三者具备胰蛋白酶原的保守结构特征,如含有催化三联体氨基酸(His-57、Asp-102和Ser-195),12个半胱氨酸,位于底物结合口袋底部Asp-189和口袋开口处的Gly-216、Gly-226等。同时,鲤3种胰蛋白酶之间具有90%以上的同源性。进化树结果显示,鲤3种胰蛋白酶均属于Group I(阴离子型胰蛋白酶),且三者的进化距离不一致。  相似文献   
3.
ABSTRACT: To reveal the ontogeny of pancreatic exocrine function in the early larval stage of eel, cDNAs encoding major pancreatic enzymes, trypsinogen, amylase and lipase were identified from the Japanese eel Anguilla japonica and their expression pattern in larvae was analyzed. The cloned eel trypsinogen precursor consisted of 224 amino acids and showed 82.2% identity to trypsinogen-2 of winter flounder Pleuronectes americanus . The eel amylase precursor consisted of 512 amino acids and showed 77% identity to winter flounder amylase. Eel pancreatic lipase was composed of 470 amino acids and had 58.3% of identity to human pancreatic lipase. In the eel larvae, mRNA expression of trypsinogen and amylase was first detected at 6 days post-hatching (d.p.h.), and the expression level increased between 7 and 8 d.p.h. In contrast, mRNA expression of lipase was first detected at 8 d.p.h. Eel larvae start to feed actively at 8 d.p.h. Thus, it was indicated that eel pancreas starts to synthesize digestive enzymes at 6 d.p.h. and acquires full function by the onset of exogenous feeding at 8 d.p.h.  相似文献   
4.
OBJECTIVE: To determine the specificity and sensitivity of plasma and urinary trypsinogen activation peptide (TAP) concentrations in diagnosing pancreatitis in dogs. DESIGN: Retrospective analysis of clinical cases. PROCEDURE: Dogs were classified into three groups: healthy animals, dogs with confirmed pancreatitis and dogs with nonpancreatic disease, which clinically or biochemically resembled pancreatitis. This last group was further subdivided into dogs with renal and those with nonrenal disease. The plasma and urinary TAP concentration was determined by a competitive enzyme immunoassay. Clinical cases additionally had serum trypsin-like immunoreactivity concentration measured, as well as radiography and ultrasound of the abdomen and further diagnostic procedures. Nonparametric analysis of variance (Kruskal-Wallis test) was performed using Statistix 4.0 program. RESULTS: There was a wide range of urinary TAP concentration in healthy dogs (mean 52.30 nmol/L, standard deviation 55.25) that made interpretation of urinary TAP concentrations difficult in the other groups. There was a narrow reference range for plasma TAP (mean 2.67 nmol/L, standard deviation 0.93). Plasma and urinary TAP concentrations, as well as urinary TAP to creatinine ratio, were all increased in dogs that died with necrotising pancreatitis. Values were not increased in mild, interstitial pancreatitis. Increased plasma TAP concentrations were also present in dogs with severe renal disease. CONCLUSION: Plasma TAP concentration is a good prognostic indicator in naturally occurring pancreatitis in dogs. The failure of TAP to increase in mild pancreatitis, and the increase present in severe renal disease, suggests its measurement has limited application as a sole diagnostic tool for canine pancreatitis. Further investigations are required in order to explain the large variability of urinary TAP concentration and the presence of circulating TAP in healthy dogs.  相似文献   
5.
采用RT-PCR和实时荧光定量PCR方法,得到黄颡鱼(Pelteobagrusf ulvidraco)消化系统胰蛋白酶原基因cDNA,并且对其早期发育过程中仔稚鱼(1~3日龄)消化系统胰蛋白酶原基因表达进行检测和定量。结果表明,黄颡鱼消化系统中胰蛋白酶原的基因表达起始于1日龄,1~6日龄表达量快速增加、6~23日龄表达量呈起伏式增加、23~30日龄表达量显著增加。该结果同时表明使用实时荧光定量PCR的方法检测黄颡鱼胰蛋白酶原基因的表达量,能反映其肠道消化功能在发育过程中的变化。建议黄颡鱼仔稚鱼转饵时间在23日龄后。  相似文献   
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