鲴鱼鱼皮胶原的提取及性质研究

利用醋酸及胃蛋白酶从鲴鱼鱼皮中提取了胶原,并对其物理与化学特性进行了探讨研究。结果表明：提取的胶原属于典型的I型胶原,胶原的三股螺旋分子组成为[a1（I）]2a2（I）。氨基酸组成及变性温度的分析说明提取的鲴鱼皮胶原由于其自身亚氨基酸含量的特征,使得它的稳定性远远高于其他鱼类的皮胶原,但仍然比大多数哺乳类动物皮胶原稳定性要弱。紫外扫描光谱、傅立叶红外光谱及圆二色性研究结果证明提取的胶原三股螺旋结构保持完整。     

胶原中氢键变化的红外光谱、拉曼光谱分析

通过红外光谱和拉曼光谱分析了皮胶原经过铝、铬、四羟甲基氯化磷鞣制前后的氢键变化,以及这3种鞣法得到的皮胶原湿热收缩前后的氢键变化。红外光谱和拉曼光谱的分析结果均显示,鞣制使得胶原分子中的氢键数量增加;鞣制过的皮胶原在湿热收缩过程中伴随着三股螺旋中酰胺羰基氢键的断裂;拉曼光谱还可以观察到脯氨酸、羟脯氨酸氢键的断裂。这一结果支持了氢键在维持胶原(包括鞣制改性的胶原)三股螺旋结构稳定的重要性,同时也为进一步研究鞣制改性皮胶原的湿热收缩机理提供了试验依据。     

鮰鱼鱼皮胶原的提取新工艺研究

研究了醋酸溶液溶胀鮰鱼鱼皮对鱼皮中胶原提取率的影响,发现先用0.5mol/L 醋酸溶胀鱼皮6h,再经组织捣碎机打浆后用稀醋酸溶解,最后用碱液中和沉淀得到粗胶原,胶原提取率可以达到92%,提取工艺简单,提取率高,耗时短。采用五种蛋白酶对提取的粗胶原进行水解以除去其中的杂蛋白,其中胰蛋白酶效果较好,除杂率为60% 以上。研究了水洗法对粗胶原的脱盐效果,所提取胶原的SDS-PAGE 显示其α链没有在提取过程中发生降解,胶原的圆二色光谱与X- 射线衍射结果表明所提取胶原基本保持了完整的三股螺旋结构,没有发生变性。     

梅花鹿鹿茸胶原的理化特性研究

对胃蛋白酶法在酸性条件下制备的梅花鹿鹿茸胶原的理化性质进行研究。通过紫外扫描(UV)、傅里叶红外光谱(FTIR)、氨基酸组成测定、聚丙烯酰胺凝胶电泳(SDS-PAGE)和示差量热扫描(DSC)等方法对其理化性质进行分析。紫外扫描图谱可知,胶原纯度较高,在230nm波长处有强吸收峰;红外光谱表明其酰胺A、酰胺B、酰胺Ⅰ谱带等主要吸收峰与Ⅰ型胶原标品一致,具有三螺旋结构;凝胶电泳表明鹿茸胶原含有α1、α2和β链,符合Ⅰ型胶原特征;氨基酸分析说明其具有典型胶原的氨基酸组成;示差量热扫描测得其热收缩温度(ts)为84.05℃。梅花鹿鹿茸具有典型的I型胶原的理化特性。     

酶法提取牛腱胶原的研究

以牛肌腱为原料,通过酶法来提取Ⅰ型胶原,找出其最佳工艺条件,并对所提取的胶原进行了性能表征。酶法水解的最佳条件:进口胃蛋白酶用量的质量分数1 % ,pH值2 .5及4℃条件下水解作用3 0h。研究结果提示:酶解法是比较理想的提取方法,不仅提取产率高,而且提取的胶原样品的分子质量高(1 0万Dal以上)且分布窄,可初步判定其基本维持了天然胶原的三股螺旋结构,适合作为生物医用材料的原料。     

鲢鱼皮、鱼鳞胶原的制备及理化特性的研究

从鲢鱼皮、鱼鳞中分别提取并纯化酸溶性和酶溶性胶原,得到四种不同的胶原,并分析四种胶原在分子组成、空间结构、热稳定性等方面的异同,为基于淡水鱼来源的胶原材料的构建提供理论依据。研究发现,四种胶原的紫外图谱、红外图谱和圆二色谱图相似,即空间结构类似,均具有天然的三股螺旋的空间构象,符合典型的Ⅰ型胶原的特点;四种胶原的氨基酸组成和比例接近;酸溶性胶原(ASC)的分子结构中二聚体β链含量多,且α1链和α3链的分子量相同,酶溶性胶原(PSC)的分子结构中二聚体β链含量少,三条α链区分明显,且鱼皮PSC和鱼鳞PSC的α链分子量分布不同;ASC溶液的粘度大于PSC,鱼皮ASC溶液的粘度大于鱼鳞ASC;四种鲢鱼胶原的热变性温度不同,即用不同方法从不同部位提取的胶原热稳定性有差异。     

海蜇伞部胶原蛋白的提取及理化性质的研究

研究海蜇(Rhopilema esculentum)伞部胃蛋白酶促溶性胶原蛋白的提取及其部分理化性质。氨基酸组成及SDSPAGE显示,海蜇伞部胶原蛋白(PSC)为Ⅰ型胶原蛋白;含糖量为2.8%;热变性温度和热收缩温度分别为28.8℃和51.6℃,均低于牛皮Ⅰ型胶原;红外光谱显示PSC 保留了大量的三股螺旋结构;溶解性表明PSC 的等电点为pH6,在pH3 时有最大溶解度;酸性条件下盐浓度高于4%(m/V)时,PSC 的溶解度急剧下降。     

鱼皮ASE、PSC的提取和性质比较

针对鱼皮胶原蛋白ASC(acid soluble collagen)和PSC(pepsin soluble collagen)的提取和性质进行研究.经过SDS-凝胶电泳初步确定其为Ⅰ型胶原,蛋白的组成为(α1)2α2,氨基酸分析两种蛋白质都具有胶原蛋白的典型特征.两种蛋白之间在分子构型、氨基酸组成等方面的差异不明显.但从黏度变化、DSC分析来看,二者之间存在一定的差异.推测差异产生的原因与蛋白质制备方法有关,非螺旋区域对三螺旋的稳定性起着重要作用,非螺旋区域的分解大大降低了PSC对热的耐受性.     

利用氧化钙从含铬革屑中提取胶原水解物的研究(Ⅱ)

利用CaO从含铬革屑中提取胶原水解物。研究了不同反应条件对胶原水解物分子质量的影响,并对反应条件为CaO用量6%(按含铬革屑质量计)、反应温度61℃、反应时间1h时所提取的胶原水解产物,进行了红外及DSC等分析。结果表明:胶原水解物与Ⅰ型胶原相比,三股螺旋结构解开,构象改变,从有序结构变为一种无序状态。     

胶原-PEO静电纺复合纳米纤维膜

将Ⅰ型胶原与聚氧化乙烯(PEO)溶解在等体积比的六氟乙丙醇与乙酸混合溶液中,经静电纺制备胶原-PEO复合纳米纤维膜。胶原与PEO的质量比分别为90∶10,80∶20和70∶30。研究了纺丝液黏度和电导率对复合纳米纤维成型与结构的影响。研究表明,随着PEO质量分数的逐渐增加,纳米纤维逐渐变细。通过傅里叶变换红外光谱测试,分析了胶原与PEO两者之间的分子作用力及胶原的三股螺旋结构,结果显示,在混纺体系中,胶原三股螺旋结构保存完整,胶原与PEO形成了较强的氢键作用。     

Studies on collagen from the skin of channel catfish (Ictalurus punctaus)

Acid-soluble and pepsin-soluble collagens (ASC and PSC) were extracted from the skin of channel catfish (Ictalurus punctaus) and partially characterized . The collagen obtained in the experiment contained more than 23% glycine as the most abundant amino acid. The denaturation temperature of acid-soluble collagen was 32.5 °C, about 5 °C lower than that of the porcine skin collagen. SDS–PAGE showed that the collagens were composed of two distinct alpha chains, which is similar to the porcine type I collagen. The contents of the skin ASC and PSC, on a dry weight basis, were 25.8% and 38.4%, respectively. These results suggest that channel catfish skin has potential as a supplement to the sources of vertebrate collagens.     

Isolation and characterisation of collagens from the skin of largefin longbarbel catfish (Mystus macropterus)

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted from the skin of largefin longbarbel catfish (Mystus macropterus) with yields of 16.8% and 28.0%, respectively, on the basis of dry weight. Both ASC and PSC contained α1 and α2 chains and the amino acid composition of collagen was close to that of calf skin type ? collagen. The intrinsic viscosities of ASC and PSC were 14.9 dl/g and 14.5 dl/g, respectively. Similar ultraviolet and FTIR spectra of ASC and PSC were observed. However, peptide maps of ASC and PSC, hydrolysed by trypsin, revealed some differences in primary structures between the two fractions. Denaturation temperatures of ASC and PSC were 32.1 °C and 31.6 °C, respectively. The higher T_m showed that it is possible to use largefin longbarbel catfish skin collagen as an alternative source of vertebrate collagens for industrial purposes.     

Isolation and characterisation of collagen extracted from the skin of striped catfish (Pangasianodon hypophthalmus)

Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the skin of striped catfish (Pangasianodon hypophthalmus) were isolated and characterised. The yields of ASC and PSC were 5.1% and 7.7%, based on the wet weight of skin, respectively, with the accumulated yield of 12.8%. Both ASC and PSC comprising two different α-chains (α1 and α2) were characterised as type I and contained imino acid of 206 and 211 imino acid residues/1000 residues, respectively. Peptide maps of ASC and PSC hydrolysed by either lysyl endopeptidase or V8 protease were slightly different and totally differed from those of type I calf skin collagen, suggesting some differences in amino acid sequences and collagen structure. Fourier transform infrared (FTIR) spectra of both ASC and PSC were almost similar and pepsin hydrolysis had no marked effect on the triple-helical structure of collagen. Both ASC and PSC had the highest solubility at acidic pH. A loss in solubility was observed at a pH greater than 4 or when NaCl concentration was higher than 2% (w/v). T_max of ASC and PSC were 39.3 and 39.6 °C, respectively, and shifted to a lower temperature when rehydrated with 0.05 M acetic acid. Zeta potential studies indicated that ASC and PSC exhibited a net zero charge at pH 4.72 and 5.43, respectively. Thus, ASC and PSC were slightly different in terms of composition and structure, leading to somewhat different properties.     

Biochemical properties of bone and scale collagens isolated from the subtropical fish black drum (Pogonia cromis) and sheepshead seabream (Archosargus probatocephalus)

Acid-soluble collagen (ASC) and pepsin-solubilized collagen (PSC) were isolated from the bones and scales of black drum (Pogonia cromis) and sheepshead seabream (Archosargus probatocephalus) caught in the Gulf of Mexico. ASC and PSC were analyzed for molecular weight by SDS–PAGE, amino acid composition, secondary structure, and denaturation temperature. The molecular masses of the collagen subunits were about 130 kDa for α₁ and 110 kDa for α₂, respectively. The amino acid composition of the PSCs was closer to that of calf skin ASC than to that of cod skin ASC. The melting temperatures of ASC and PSC were >34 °C. Intrinsic viscosity of the PSCs was similar to the intrinsic viscosity of collagen from fish species such as hake, cod, and catfish. Black drum and sheepshead bone and scale collagens were typical type-I collagens and may find applications in the functional food, cosmetic, biomedical, and pharmaceutical industries.     

Characterization of acid- and pepsin-soluble collagens from flatfish skin

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from flatfish skin were characterized. The yield of PSC was 85.5%, which was higher than that of ASC at 57.3%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns showed that both the ASC and PSC were consisted of α1 and α2 chains, and β-chain. According to the results of Fourier transform infrared (FTIR) spectroscopy and hydroxylation, no difference in the helical structure between ASC and PSC was found. Thermal denaturation temperature (TDT) of flatfish skin collagen was 26.6°C for ASC and 26.7°C for PSC, which were similar to those of temperate fishes, while were lower compared to tropical fishes, such as the conger eel and Nile perch. There was no solubility difference between ASC and PSC at various pH and NaCl concentrations. Therefore, PSC will be preferable compared to ASC for commercial uses because of its higher yield.     

Biochemical properties of skin collagens isolated from black carp (Mylopharyngodon piceus)

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted with the yield of 15.5 and 26.5% on the basis of dry weight from the skin of black carp (Mylopharyngodon piceus). ASC and PSC were similar in amino compositions and subunit compositions, but they were slightly different in the secondary structure. Both of ASC and PSC, either rehydrated in distilled water or in acetic acid, had a lower denaturation temperature than pig skin collagen (PPSC), but their denaturation temperature were higher than that of collagens from other freshwater fish. Intrinsic viscosity of different collagens decreased in the order of PPSC>PSC>ASC. Both of ASC and PSC showed only partial degradation in collagenase solution, but they revealed more sensitive to collagenase compared with PPSC. Black carp skin collagens did not induce a significant cytotoxic effect according to the results of in vitro cytotoxicity test.     

Collagens from the skin of arabesque greenling (Pleurogrammus azonus) solubilized with the aid of acetic acid and pepsin from albacore tuna (Thunnus alalunga) stomach

BACKGROUND: Due to the low extraction efficiency of collagen from fish skin by the typical acid solubilization process, pepsin has been widely used to aid further extraction of collagen from the residue. The aim of this study was to characterize collagen from the skin of arabesque greenling extracted with the aid of albacore tuna pepsin, in comparison with collagen obtained from the acid solubilization process. RESULTS: Acid‐solubilized collagen (ASC) from the skin of arabesque greenling was extracted with acetic acid. Pepsin‐solubilized collagen (PSC) was further extracted from the skin residue with the aid of pepsin from albacore tuna. The yields of ASC and PSC were 303 and 140 g kg^?1 (dry weight), respectively. Both collagens contained α‐ and β‐chains as their major components and were characterized as type I collagen. Both collagens contained glycine as a major amino acid and had imino acid content of 157–159 residues per 1000 residues. The degradation induced by lysyl endopeptidase and V8‐protease was more pronounced in PSC compared with ASC. Maximal transition temperatures of both collagens were in the range of 15.4–15.7 °C. Fourier transform infrared spectra revealed some differences in molecular order between ASC and PSC. Nevertheless, the triple‐helical structure of PSC was still predominant. Based on ζ‐potential, pI of ASC and PSC was estimated to be 6.31 and 6.38, respectively. CONCLUSION: Isolation of collagens from the skin of arabesque greenling could be achieved by acid or albacore tuna pepsin solubilization. However, there was a slight difference in properties between ASC and PSC. Copyright © 2010 Society of Chemical Industry     

草鱼皮酸溶性和酶溶性胶原蛋白的提取及性质

本文研究了从草鱼皮中提取酸溶性胶原蛋白(ASC)和酶溶性胶原蛋白(PSC)及其部分性质。草鱼皮中ASC和PSC的提取得率以干基计分别为8.0%和18.6%;对草鱼皮ASC和PSC的紫外光谱分析,最大吸收峰都接近223nm;SDS-PAGE电泳图谱显示草鱼皮胶原蛋白是由两条不同的α链组成,分子量都在100kDa以上,与猪皮I型胶原蛋白相似;草鱼皮ASC和PSC热变性温度分别为33.8、34.5℃,只比猪皮的热变性温度(37℃)低3℃左右。结果表明草鱼皮胶原蛋白在功能食品、医药、化妆品、制药等方面有潜在的应用。     

Isolation and Characterisation of collagen from the skin of brownbanded bamboo shark (Chiloscyllium punctatum)

Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the skin of brownbanded bamboo shark (Chiloscyllium punctatum) were isolated and characterised. The yield of ASC and PSC were 9.38% and 8.86% (wet weight basis), respectively. Based on protein patterns and TOYOPEARL^® CM-650M column chromatography, both collagens contained α- and β-chains as their major components. These were characterised as type I collagen with the cross-link of α2-chain. As digested by V8-protease and lysyl endopeptidase, peptide maps of both ASC and PSC were similar, but differed from that of type I collagen from calf skin. Fourier transform infrared (FTIR) spectra of both collagens were similar and pepsin hydrolysis had no effect on triple-helical structure of collagen. Transition temperature (T_max) of ASC and PSC were 34.45 and 34.52 °C, respectively, as determined by differential scanning colorimetry (DSC). From zeta potential study, the isoelectric points of ASC and PSC were estimated to be 6.21 and 6.56, respectively. Therefore, the skin of brownbanded bamboo shark could serve as an alternative source of collagen for different applications.     

Characteristics of collagen from the skin of clown featherback (Chitala ornata)

Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the skin of clown featherback (Chitala ornata) were isolated and characterised. Yields of ASC and PSC were 27.64 and 44.63% (dry weight basis) with total collagen recovery of 82.08%. Both collagens contained glycine as the major amino acid with relatively high content of proline, hydroxyproline and glutamic acid/glutamine. Nevertheless, they had the low content of cysteine, histidine and tryrosine. The collagen was characterised as type I, comprising (α1)₂α2‐heterotrimer. Pepsin‐aided process did not affect triple‐helical structure of PSC as determined by FTIR spectra. Thermal transition temperature of ASC (36.28 °C) was slightly higher than that of PSC (35.23 °C). However, no differences in isoelectric point (5.54–5.68) between ASC and PSC were observed. Therefore, collagen from the skin of clown featherback could be successfully extracted for further applications.