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1.
ABSTRACT: Grammistins are hemolytic and ichthyotoxic peptides in the skin secretion of soapfishes and are structurally characterized by their abundance in amphiphilic α-helicity. In the present study, their interaction with lipids and lipid vesicles as well as antibacterial activity were examined using four grammistins (Gs 1 and Gs 2 from Grammistes sexlineatus and Pp 1 and Pp 3 from Pogonoperca punctata ). The hemolytic activity of grammistins was inhibited by phospholipids but not by cholesterol. Moreover, grammistins released carboxyfluorescein entrapped within liposomes made of phosphatidylcholine. In contrast, grammistins were found to have antibacterial activity with a broad spectrum against nine species of bacteria, including both Gram-negative and Gram-positive groups. The potency of their antibacterial activity was not related to that of hemolytic activity, suggesting that grammistins bind to membrane phospholipids but lyse erythrocyte and bacterial membranes via different mechanisms. Conclusively, grammistins are new members of the family of cell non-selective membrane-lytic peptides with amphiphilic α-helices, being similar to pardaxins, which are secreted from the skin of soles, and to melittin, which is derived from bee venom. 相似文献
2.
Grammistins, peptide toxins isolated from the skin secretions of two species of soapfishes Grammistes sexlineatus and Pogonoperca punctata, are new members of the family of linear membrane-lytic antibacterial peptides characterized by the abundance of amphiphilic
α-helices. As the first step toward future use of grammistins to examine the mode of membrane lysis and design new antibiotics,
C-terminally free and amidated forms were chemically synthesized for each of five grammistins (Gs 1, Gs 2, Pp 1, Pp 2b and
Pp 3), and evaluated for hemolytic and antibacterial activities. No difference in biological activities was observed between
C-terminally free and amidated forms of Gs 1, while the C-terminally amidated forms of the other grammistins exhibited much
higher activities than the C-terminally free forms. Comparison with the biological activities of natural grammistins, together
with our preliminary cloning experiments, showed that natural grammistins, except for Gs 1, are C-terminally amidated. As
for Pp 1, six analogous peptides were further synthesized. Determination of their biological activities revealed that the
amphiphilic α-helical structure and positive charge are important for the hemolytic and antibacterial activities, respectively,
of Pp 1. 相似文献
3.
Jian Sun Zhou Yang PeiZhen Xiao Yong Liu Hong Ji ZhenYu Du LiQiao Chen 《Fish physiology and biochemistry》2017,43(2):539-547
4.
为制备抗氧化活性良好的鲢鱼鱼皮蛋白肽,采用胰蛋白酶、碱性蛋白酶、菠萝蛋白酶和木瓜蛋白酶等4种常见的商业酶对鲢鱼鱼皮进行酶解,测定酶解物的ABTS自由基清除力和Fe2+螯合力来评价其抗氧化活性,并用超滤及凝胶层析对酶解物进行分离,以期得到活性更好的酶解物分离组分。酶解后产物的抗氧化活性均有所提高,其中碱性蛋白酶酶解2 h产物活性较强。对此酶解物用截留分子量为10 k Da、5 k Da和3 k Da的中空纤维超滤膜进行超滤,得到的4个组分中,分子量越小的组分抗氧化活性越强。分子量小于3 k Da的组分经Sephadex G-15凝胶层析得到3个组分,其中分子量最大的组分活性较好,在0.51 mg/m L质量浓度下测定其ABTS自由基清除率和Fe~(2+)螯合力分别为(79.65±0.87)%和(93.40±0.20)%。该研究成果对鲢鱼鱼皮抗氧化肽的开发具有较好的指导作用。 相似文献
5.
Asuncin Lago-Lestn Elizabeth Ponce Ma. Enriqueta Muoz 《Aquaculture (Amsterdam, Netherlands)》2007,270(1-4):343-357
6.
Erika M. Plisetskaya 《Fish physiology and biochemistry》1989,7(1-6):39-48
From the very beginning of physiological studies on the endocine pancreas, fish have been used as experimental subjects. Fish
insulin was one of the first vertebrate insulins isolated and one of the first insulins whose primary and then tertiary structures
were reported. Before a second pancreatic hormone, glucagon, was characterized, a physiologically active ‘impurity’, similar
to that in mammalian insulin preparations, was found in fish insulins.
Fish have become the most widely used model for studies of biosynthesis and processing of the pancreatic hormones. It seems
inconceivable, therefore, that until the recent past cod and tuna insulins have been the only purified piscine islet hormones
available for physiological experiments. The situation has changed remarkably during the last decade.
In this review the contemporary status of physiological studies on the fish pancreas is outlined with an emphasis on the following
topics: 1) contents of pancreatic peptides in plasma and in islet tissue; 2) actions of piscine pancreatic hormones in fish;
3) specific metabolic consequences of an acute insufficiency of pancreatic peptides; 4) functional interrelations among pancreatic
peptides which differ from those of mammals. The pitfalls, lacunae and the perspectives of contemporary physiological studies
on fish endocrine pancreas are outlined. 相似文献
7.
Tsuyoshi Komai Choko Kawabata Hiroaki Tojo Shinobu Gocho Eiji Ichishima 《Fisheries Science》2007,73(2):404-411
ABSTRACT: An acidic serine carboxypeptidase (CPase Tpa) from the hepatopancreas of Japanese common squid Todarodes pacificus was purified. Purified CPase Tpa had a molecular mass of 36 kDa on sodium dodecylsulfate–polyacrylamide gel electrophoresis, and an isoelectric point of 6.0. The optimum pH of CPase Tpa was pH 4.0. In investigating the specificity of CPase Tpa for several peptide substances, it was found that peptides with hydrophobic or bulky amino acid residues at the P1 position reacted well. The enzymatic activity was almost completely inhibited by p -chloromercuribenzoic acid, monoiodoacetic acid, diisopropylfluorophosphate and HgCl2 . This is the basis for its grouping in the serine carboxypeptidase family (EC 3. 4. 16. 5). The substrate specificity of CPase Tpa can be used to eliminate the bitterness of bitter peptides. In this study, the bitterness-reductive effect using bitter peptides prepared by hydrolyzing soy protein, casein and corn gluten with pepsin or trypsin was tested. The bitterness of soy peptide digested with pepsin was completely eliminated by treatment with CPase Tpa, whereas the bitterness of casein digested with trypsin and corn peptide digested with pepsin were somewhat less efficient. On the basis of these results, it is anticipated that CPase Tpa would be effective in eliminating the bitterness of some bitter peptides. 相似文献
8.
三倍体湘云鲫2号具有不育、生长快、抗病抗逆性强等优良特性。为探究其抗病优势分子机制,实验克隆及鉴定了三倍体湘云鲫2号干扰素a3(3nIFNa3)。3nIFNa3的CDS由552个核苷酸组成,编码184个氨基酸。经预测,3nIFNa3 N端23位氨基酸为信号肽;3nIFNa3成熟肽中存在2个半胱氨酸残基并参与形成二硫键,表明其隶属于Ⅰ型一组干扰素。实时荧光定量PCR (qPCR)结果显示,宿主细胞经poly I∶C刺激后8 h、草鱼呼肠孤病毒(GCRV)或鲤春病毒血症病毒(SVCV)感染后48 h,3nIFNa3的转录水平达到最高。免疫印迹和免疫荧光结果显示,3nIFNa3为分泌型蛋白,分子量约为21.8 ku,其在出胞前主要分布于细胞质中。进一步研究发现,在宿主细胞中过表达3nIFNa3或含3nIFNa3的上清培养基孵育宿主细胞均能诱导内源ISG基因转录水平的显著提高。其中,3nSTAT1及3nVIPERIN在含3nIFNa3的上清培养基孵育后2 h转录水平达到最高,3nPKR则在4 h表达水平最高。此外,病毒滴度测定及结晶紫染色实验表明,EPC细胞经3nIFNa3孵育或过表达3nIFNa3后,其抗GCRV和SVCV的能力均显著增强。研究表明,3nIFNa3为可分泌的细胞因子,在宿主抗病毒天然免疫反应中发挥作用。 相似文献
9.
Abstract. Skin lesions developed on channel catfish, Ictalurus punctatus , exposed to 0-5 mg/1 Furanace for 4 or 14 days. Lesions developed 3 days after the 4-day exposure and on the eleventh day of the 14-day exposure. The lesions continued to develop after the fish were moved to untreated water. The lesions which began as dull areas of skin, sometimes resulted in erosion of skin and muscle which exposed the vertebrae. Bacteria were not isolated from the lesions except those with severely eroded muscle. The gills possessed lesions characteristic of a response to a toxic chemical agent. 相似文献
10.
In the present study, a total of 150 samples including 50 salted anchovy, 50 raw anchovy, and 50 raw mussel samples collected from the retailers and small-scale producers in Samsun province from the Black Sea region of Turkey were analyzed; and 12% (6/50), 2% (1/50), and 2% (1/50) of the samples, respectively, were found to be contaminated with L. monocytogenes. According to the serotype distribution, six salted anchovy and one of the raw fish samples were contaminated with L. monocytogenes 1/2b (or 3b). In one raw mussel, both L. monocytogenes 1/2b (or 3b) and 4b (or 4d or 4e) serotypes were detected. 相似文献
11.
In vivo andin vitro techniques were used to examine the influence of various vertebrate peptides on growth hormone (GH) secretion in the goldfish.
Tetradecapeptide somatostatin (SRIF-14) was found to inhibit GH secretionin vitro from perifused pituitary fragments, whereas similar concentrations of a salmonid SRIF peptide (sSRIF-25) did not affect GH
secretion from the goldfish pituitary fragments. This indicates that SRIF receptors on the goldfish pituitary are very specific
for SRIF-14-like peptides. Salmon gonadotropin (GTH)-releasing hormone (sGnRH) was found to elevate serum GH levels in male
goldfish. The dopamine antagonist pimozide alone or injected in combination with sGnRH did not influence serum GH levels,
although injection of pimozide alone significantly elevated serum GTH levels, in addition to potentiating the effects of sGnRH
on GTH secretion. sGnRH stimulated GH secretion from goldfish pituitary fragmentsin vitro, indicating that sGnRH acts directly at the level of the pituitary to stimulate GH secretion in the goldfish. These results
suggest that GnRH may also function as a GH-releasing factor in the goldfish, although the release-inhibitory factors for
GH and GTH secretion do appear to be separate and distinct. Two human GH-releasing hormone (hGHRH) peptides were found to
be ineffective in altering GH secretionin vitro from the perifused pituitary fragments. Consequently, a role for a mammalian GHRH-like peptide in the hypothalamic regulation
of GH secretion in the goldfish remains questionable. 相似文献
12.
氟苯尼考及氟苯尼考胺在鲤体内的残留 总被引：1，自引：0，他引：1
在水温(18±1)℃下,采用高效液相色谱串联质谱法研究了氟苯尼考及其主要代谢物氟苯尼考胺在体质量(100±10)g鲤(Cyprinus carpio)体内的代谢及残留规律,以制定休药期。实验鱼间隔24h按15 mg.kg-1体质量的剂量口灌给药,连续给药3次,在给药后0.5h、1 h、2h、4h、8h、12h、24h、2d、3d、5d、7d、10d、15d、20d检测肌肉、皮肤内氟苯尼考和氟苯尼考胺的含量。结果表明:氟苯尼考在鲤体内的代谢速度快,2~4 h出现峰值;肌肉中氟苯尼考和氟苯尼考胺的残留浓度高于皮肤,肌肉和皮肤中氟苯尼考的含量均高于氟苯尼考胺,皮肤中的代谢速度较快。按欧盟标准相应的休药期不少于2d,按日本标准则不少于10 d。 相似文献
13.
Abstract. Cryptocaryon irritans (Ciliophora), isolated from the reef fish, Grammistes sexlineatus Thumberg, was established as primary infections in mullet, Chelon labrosus (Risso). Only a small percentage (<22%) of exposed theronts established infection under controlled conditions. This is discussed in relation to the probability of host parasite contact and susceptibility. There was no evidence of density-dependent or intra-specific competition in trophont establishment, a strong linear relationship being found between the levels of exposure and infection. Infection intensity was assessed in relation to host survival, indicating a 90% probability of host death following levels of >200 trophonts per gram of host. A close temporal association between host death and trophont exit was found, possibly as a result of epidermal disruption leading to dysfunction of osmoregulatory and respiratory systems. 相似文献
14.
Four small identical tanks fed with power station effluent were each stocked with 10 × “1-group” plaice. The fish in each of the tanks were fed minced fish containing different binding agents. Bacteria were isolated from skin and intestinal samples of two fish taken from each tank. Five generic/group generic types were isolated from fish skin while ten types were isolated from fish intestines. Organisms belonging to the Enterobacteriaceae were isolated from both skin and intestines. The types isolated from intestines also included Aeromonas species (spp.). However, strict anaerobes were unable to be isolated.All intestinal bacteria were tested for their ability to grow on a minimal salt agar medium containing each of the binders as sole carbon source. There was no special relationship between the binder to which the isolates were exposed in the fish intestine and the binders which they could utilise as sole carbon sources. Few isolates could utilise hydroxypropyl-methyl cellulose. 相似文献
15.
Cryptocaryon irritans Brown, 1951 (Ichthyophthiriidae): the ultrastructure of the somatic cortex throughout the life cycle 总被引：1，自引：0，他引：1
Abstract. Cryptocaryon irritans was isolated from Grammistes sexlineatus and maintained in aquaria under controlled conditions using the mullet, Chelon labrosus (Risso), as an experimental host. The pellicle and cortical cytoplasm of the trophont, tomont, tomite and theront stages were investigated with the aid of transmission electron microscopy. The general structural organization of the pellicle resembles that of the freshwater holotrich, Ichthyophthirius multifiliis ; however, the pellicular alveoli are characterized by the accumulation of electron-dense material in the trophont, tomite and theront, this material being lost in the newly-encysted tomont. The outer membranes of the pellicle are infolded into the alveoli of the trophont. Cilia are present at all stages of the life cycle, although at encystment their numbers are greatly reduced by shedding. Mitochondria, mucocysts and Golgi-like cisternae are distributed throughout the cortical cytoplasm. Mucocysts differ from those of I. multifiliis in size, shape and distribution and are of uniform electron density. The role of the pellicle and cortical cytoplasm is discussed in relation to the invasion of the fish epidermis, possible intertransferance of materials between parasite and host and the process of encystment. 相似文献
16.
Wanticha Savedboworn Soottawat Benjakul Sittichoke Sinthusamran Hideki Kishimura 《Journal Of Aquatic Food Product Technology》2017,26(3):248-257
Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were isolated from rohu skin with the yield of 64.2 and 6.8% (dry weight basis), respectively. Both collagens had glycine as the major amino acid with imino acid content of 196–202 residues/1,000 residues and were characterized as type I collagen with molecular composition of (α1)2α2-heterotrimer. Fourier transform infrared spectra of both collagens were similar, with no shift in wavenumber of all amide bands. The Tmax value of ASC and PSC was 36.40 and 35.48°C, respectively. The zero surface net charge of ASC and PSC was found at pH 5.9 and 5.3, respectively. 相似文献
17.
Significant numbers of perch, Perca fluviatilis, raised on a pilot fish farm in Switzerland presented focal skin lesions on the lateral sides and fin rot. Mortality rates reached levels of up to 1% of the total fish on the farm per day. Virtually pure cultures of Aeromonas sobria were isolated from the liver, kidney, spleen and skin lesions of affected fish. Aeromonas sobria isolated from the farmed perch had a haemolytic effect on sheep and trout erythrocytes, autoaggregated, was cytotoxic for cultured fish cells and possessed genes involved in type III protein secretion. Experimental infection of naive perch with a single colony isolate of A. sobria from an affected farm fish resulted in the development of clinical signs identical to those seen on the farm. The results indicate that A. sobria can act as a primary pathogen of perch. 相似文献
18.
Mei-Qin Zhuo Ya-Xiong Pan Kun Wu Yi-Huan Xu Li-Han Zhang Zhi Luo 《Fish physiology and biochemistry》2017,43(3):719-730
19.
Yanjie Li Qingfeng He Xiaodan Li Ailin Zhang 《Journal Of Aquatic Food Product Technology》2019,28(6):637-648
Half-smooth tongue sole is a popular warm-water fish, and its skin may be an available resource for gelatin extraction. Response surface method was used to optimize the extraction of gelatin from the fish skin. The most suitable conditions for maximum gelatin yield (24.2%) were pretreatment with 1.9 g/L NaOH, followed by hot water extraction at 63.54ºC for 4.81 h. The obtained gelatin had a high imino acid content (185 residues/1,000 residues), with a high content of crude protein and low levels of ash, fat, and moisture. The predominant sodium dodecyl sulfate–polyacrylamide gel electrophoresis bands revealed that the gelatin contained low-molecular-weight peptides, α-, β-, and γ chains. As compared with bovine gelatin, the fish skin gelatin solution had lower values of strength and clarity and higher levels of L* and viscosity. Additionally, Fourier-transform infrared spectra showed that gel from the gelatin had four amide bands (amide A, amide I, amide II, and amide III) similar to commercial gelatin. The results suggest that half-smooth tongue sole skin could be a promising source of gelatin in view of the comparability between its gelatin and commercial gelatin in physicochemical properties. 相似文献
20.
为探明鱼类消化液分泌的相关调控因子,采用RACE技术分别克隆了鳜(Siniperca chuatsi)两种肠道激素——胃泌素(gastrin,GAS)与胆囊收缩素(cholecystokinin,CCK)基因的cDNA序列。鳜GAS基因cDNA全长581 bp,5′非翻译区长100 bp,3′非翻译区长145 bp,开放阅读框长336 bp,编码111个氨基酸;鳜CCK具有2种类型:CCK1与CCK2,CCK1 cDNA全长为843 bp,5′非翻译区长60 bp,3′非翻译区长369 bp,开放阅读框414 bp,编码137个氨基酸;CCK2 cDNA全长846 bp,5′非翻译区长112 bp,3′非翻译区长332 bp,开放阅读框403 bp,编码134个氨基酸。鳜GAS与CCK成熟肽C末端具有相似的八肽结构(DYQGWVDF/DYLGWMDF),仅在C末端第3位和第6位氨基酸发生替换。荧光定量PCR分析表明,鳜GAS mRNA主要表达于肠和幽门垂,CCK1与CCK2 mRNA在脑中表达量最高,在肠和幽门垂也有较高表达,表明GAS与CCK同为消化调控因子,而CCK还是神经分泌因子。鳜GAS与CCK mRNA表达贯穿于整个幼体早期发育阶段(孵化后0～22 d),前期表达水平较高,后期表达水平较低,并趋于平稳,GAS与CCK mRNA发育表达水平变化可能与这一时期消化道生长发育旺盛有关。 相似文献