斑点叉尾鮰鱼皮胶原蛋白的理化特征研究

选用斑点叉尾鮰(Ictalurus punctatus)鱼皮为材料,用乙酸和乙酸-胃蛋白酶,分别提取鱼皮中的酸溶性胶原蛋白(acid-solubilise collagen,ASC)和酶溶性胶原蛋白(pepsin-solubilise collagen,PSC),并对其理化性质特征进行研究研究发现,提取得到的ASC纯度高达93.11％,PSC纯度高达93.46％;紫外吸收分析表明,ASC和PSC的吸收峰值均在233nm处;蛋白图谱中两种胶原蛋白均由两种不同的α链(α1) 2α2组成,具备Ⅰ型胶原蛋白的特征;ASC和PSC的傅里叶红外图谱相似,具有完整的三螺旋结构;ASC的变性温度为34.2℃,PSC的变性温度为33.9℃.     

草鱼鱼鳞、鱼皮和鱼骨酸溶性胶原蛋白特性对比研究

从草鱼鱼鳞、鱼皮和鱼骨中提取酸溶性胶原蛋白(ASC),对其特性进行对比分析。紫外光谱和电泳图谱结果显示,3种ASC紫外特征吸收峰出现位置与I型胶原蛋白紫外特征吸收峰出现的位置基本一致,分子结构都至少含有两条α链;傅里叶红外光谱显示,草鱼鱼鳞、鱼皮和鱼骨ASC在酰胺A带的N-H伸缩均以氢键形成缔合体,酰胺Ⅰ带和酰胺Ⅲ带的特征吸收峰表明鱼鳞和鱼骨ASC的α-螺旋结构保存较完整,鱼皮ASC的α-螺旋结构已经被破坏;3种ASC在热稳定性方面存在一定差异,热变性温度鱼骨ASC(34.5℃)鱼皮ASC(32℃)鱼鳞ASC(31℃),可能与胶原存在的组织和所处的环境有关。     

不同方法提取鲢鱼皮胶原蛋白的理化特性比较

本文分别采用酸法(ASC)、酶法(PSC)和热水浸提法(HWSC)提取鲢鱼皮胶原蛋白,考察不同提取方法对鱼皮胶原蛋白理化性质的影响。研究表明,3种方法所提取的鱼皮胶原蛋白的紫外吸收光谱、红外吸收光谱都较为相似,在232 nm处均出现胶原蛋白的最大吸收峰,在280 nm处几乎无吸收;SDS-PAGE电泳图谱显示3种方法所提取的胶原蛋白,其亚基组成形式均为(α1)2α2,同时,3种方法所提取的胶原蛋白其氨基酸组成和比例类似,均符合Ⅰ型胶原蛋白特征。热水浸提法所提取的鱼皮胶原蛋白(HWSC)羟脯氨酸含量较低,凝胶特性较好,酸法提取对胶原蛋白空间网络结构影响最小。ASC、PSC和HWSC的热变性温度分别为31.05±0.14℃、31.45±0.01℃、43.75±1.20℃。不同提取方法对鱼皮胶原蛋白的羟脯氨酸含量、流变学特性、热变性温度及微观结构有一定的影响。     

鲟鱼皮胶原蛋白的理化特性研究

本文以俄罗斯鲟鱼皮为原料,采用酸法和酶法提取胶原蛋白,研究了酸溶性胶原蛋白(ASC)和酶促溶性胶原蛋白(PSC)的蛋白类型、结构、热变性温度和溶解度等理化性质,并与牛跟腱I型胶原蛋白(BATC)进行比较。SDS-PAGE电泳图显示ASC和PSC均包含了两条α链(α1链和α2链),为I型胶原蛋白;傅立叶红外光谱图表明提取的2种胶原蛋白均保存了完整的三螺旋结构,但ASC的有序度相对较高;ASC和PSC的热变性温度分别为32.48℃和32.68℃,低于BATC;在酸性pH条件下(pH 1~4),ASC和PSC溶解度较高,当Na Cl浓度大于2%时,PSC的溶解度较高;扫描电镜显示2种胶原蛋白均为网状结构,ASC的孔径较均匀,且孔径较小。上述结果表明提取方法不同,导致2种胶原蛋白的理化性质具有一定的差异,但都具有较好的热稳定性、溶解性,能形成较好的网状结构,有潜力的作为胶原蛋白的替代来源。     

单环刺螠体壁胶原蛋白的提取及其理化性质

采用0.5mol/L醋酸提取,结合NaCl沉淀法从单环刺螠(Urechis unicinctus)的体壁中提取酸溶性胶原蛋白(ASC),并对其理化性质作初步研究。紫外光谱分析表明ASC的特征吸收波长位于228nm,初步推断所提取的蛋白为典型的胶原蛋白;氨基酸组成分析表明ASC为典型的Ⅰ型胶原蛋白;聚丙烯酰胺凝胶电泳(SDS-PAGE)结果表明ASC有两条不同的α链(α1和α2链)、β链和γ链,其胶原蛋白中含有二硫键;傅里叶红外光谱(FTIR)分析表明其存在三螺旋结构;示差扫描量热仪(DSC)分析表明热变性温度(td)和热收缩温度(ts)分别为33.6℃和67.5℃。     

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。     

鲤鱼鱼皮和鱼骨酶溶性胶原蛋白性质异同的分析

本研究对以鲤鱼鱼皮和鱼骨为原料得到的两种酶溶性胶原蛋白(PSC)的性质进行比较分析。结果表明,两种胶原蛋白中脯氨酸和羟脯氨酸含量均低于牛皮酸溶性胶原蛋白;黏度法测定鱼皮PSC的变性温度为28.1℃,鱼骨PSC的变性温度为30.0℃;DSC分析的结果也说明鱼骨PSC的热稳定性高于鱼皮PSC;电泳结果表明,鱼皮PSC和鱼骨PSC的肽链组成和多肽链的分子量相近,二者具有很大的相似性。     

鲢鱼皮胶原蛋白的提取及性质分析

通过热水浸提,醋酸酸提及胃蛋白酶促提从鲢鱼皮中提取得到水溶性胶原蛋白(RSC),酸溶性胶原蛋白(ASC)和酶溶性胶原蛋白(PSC),并分析其部分性质。鲢鱼皮中RSC,ASC和PSC的得率以湿基计分别为13.2%,11.8%和13.6%;RSC,ASC和PSC的紫外光谱分析表明,其最大吸收峰都接近231 nm,但在280 nm处的吸收很小;傅立叶变换红外光谱结果表明鲢鱼皮胶原蛋白具有特殊的三螺旋结构;SDS-PAGE电泳图谱显示鲢鱼皮胶原蛋白有两条α链(α1和α2)和β链,表明该胶原为典型的I型胶原蛋白;鲢鱼皮RSC,ASC和PSC热变性温度分别为27.1℃,31.3℃和30.5℃。这些结果为进一步研究提供了理论依据。     

鮟鱇鱼皮中胶原蛋白的提取及性质研究

采用0.5 mol/L醋酸提取,结合NaCI沉淀法从鮟鱇鱼皮中提取酸溶性胶原蛋白(ASC).并对鮟鱇鱼皮胶原蛋白与Sigma公司的牛跟腱I型胶原蛋白(BATC)进行比较,探讨二者在热变性温度、溶解度、黏度及氨基酸组成等方面的差异.SDS-PAGE结果显示ASC有2条α链(α1和α2链)、β链和γ链,表明该胶原为典型的I型胶原蛋白.DSC分析显示两种胶原的热变性温度分别为22.09℃和38.13℃.氨基酸组成分析结果是亚氨基酸含量ASC低于BATC,分别为14.69%和21.59%;甘氨酸含量相近,分别占所有氨基酸总数的40.05%和38.97%.溶解度结果显示ASC和BATC分别在pH 3和pH 4时达到最大值,在pH 7时两者都呈现最小溶解度;NaCl含量对两者溶解度的影响相同,当其含量低于2%时对溶解度的影响不明显,而随着NaCl舍量的增加,溶解度迅速下降.     

鲤鱼鱼皮和鱼骨酶溶性胶原蛋白的性质比较

以鲤鱼鱼皮和鱼骨为原料提取得到酶溶性胶原蛋白(PSC),对鱼皮PSC和鱼骨PSC的性质进行比较。电泳结果表明,鱼皮PSC和鱼骨PSC都属于Ⅰ型胶原;2种胶原蛋白中,脯氨酸和羟脯氨酸含量均低于牛皮酸溶性胶原蛋白;粘度测定的结果显示,鱼皮PSC的变性温度为28.1℃,鱼骨PSC的变性温度为30.0℃;差热分析的结果说明,鱼骨PSC的热稳定性高于鱼皮PSC,这与氨基酸分析和粘度分析的结果相一致;傅立叶红外光谱分析结果显示,鱼皮PSC和鱼骨PSC结构具有很大的相似性。     

Properties of collagen from skin,scale and bone of carp (Cyprinus carpio)

Carp (Cyprinus carpio) is one of the main species of freshwater fish produced in China. Acid-soluble collagens (ASC) were prepared from carp skin, scale and bone. The yields of skin ASC, scale ASC and bone ASC are 41.3%, 1.35% and 1.06% (on the dry weight basis), respectively. SDS–PAGE pattern showed that ASCs of carp skin, scale and bone were all type I collagen, which were composed of two α₁ and one α₂ chains. The molecular weight of α₂ chain is 116 KDa. The amino acid composition and peptide maps of ASCs were similar to each other, but they were totally different from those of cod skin ASC. Denaturation temperatures (T_d) of ASCs were around 28 °C. Fourier transform infrared spectroscopy proved that ASCs were integrate and native. The results suggest that carp skin, scale and bone collagens have potential as an alternative source of collagen for use in various fields.     

冬夏鲤鱼鱼皮和鱼骨胶原蛋白稳定性比较

从冬季(2008 年2 月)和夏季(2008 年7 月)的鲤鱼鱼皮和鱼骨中分别提取酸溶性胶原蛋白,在一定温度下加热,通过蛋白酶的酶解和圆二色谱(CD)法研究其热稳定性。结果显示：冬季鱼皮和鱼骨酸溶性胶原蛋白的变性温度分别为31.0℃和 32.8℃,比夏季鱼皮和鱼骨酸溶性胶原蛋白的变性温度分别低1.0℃和0.6℃。通过圆二色谱(CD)法得到了与此一致的结果。测定结果显示,来源于夏季鱼皮和鱼骨胶原蛋白的热稳定性要优于冬季鱼皮和鱼骨胶原蛋白。     

Comparative study on molecular characteristics of acid soluble collagens from skin and swim bladder of seabass (Lates calcarifer)

Acid soluble collagens (ASCs) from skin and swim bladder of seabass (Lates calcarifer) were isolated and comparatively characterised. Higher yield (28.5%) was obtained for ASC from swim bladder, compared with that from skin (15.8%). ASCs from both skin and swim bladder had the similar protein patterns and were identified to be type I. Both α- and β-chains constituted as major components. Fourier transform infrared (FTIR) spectra revealed that both ASCs were triple helix in structure. ASC from both sources contained glycine as the major amino acid with imino acids (proline and hydroxyproline) of 194–195 residues/1000 residues). Peptide maps of both ASCs digested by chymotrypsin and trypsin showed slight differences, suggesting some differences in their primary structure. The thermal transition temperature of swim bladder ASC (35.02 °C) was slightly higher than its skin counterpart (33.33 °C). Based on zeta potential analysis, ASCs from skin and swim bladder had a net charge of zero at pH 6.46 and 6.64, respectively. Therefore, both the skin and swim bladder of seabass could be used potentially for collagen extraction.     

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.     

Characterisation of acid-soluble collagen from skin of silver carp (Hypophthalmichthys molitrix)

Acid-soluble collagen (ASC) from the skin of silver carp (Hypophthalmichthys molitrix) was isolated and some properties of ASC were investigated. SDS–PAGE patterns showed ASC from silver carp skin was type ? collagen. Sulfopropyl-Toyopearl 650(M) column chromatography indicated that ASC from silver carp skin was composed of three kinds of α chains, α₁, α₂ and α₃. Hydroxyproline and proline content of ASC from silver carp skin was 192 residues/1000 residues, which was similar to that of ASC from carp skin. Denaturation temperature (T_d) of ASC from silver carp skin was around 29 °C. The results showed that some properties of ASC from silver carp skin were similar to those of ASC from carp skin. However, the peptide map of ASC from silver carp skin digested by pepsin was distinguished with that of ASC from carp skin.     

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.     

Acid‐soluble and pepsin‐soluble collagens from grass carp (Ctenopharyngodon idella) skin: a comparative study on physicochemical properties

In this study, acid‐soluble (ASC) and pepsin‐soluble (PSC) collagens with triple helical structures were successfully extracted from the skin of grass carp (Ctenopharyngodon idella) by two different extraction approaches. SDS‐PAGE pattern revealed that ASC and PSC are type I collagens with typical α1, α2 and β‐chains. In addition, the intensity of χ‐chain (trimer) in ASC was higher than that of PSC, representing the presence of the high proportion of intra‐ and intermolecular cross‐links of extracted collagens with large molecular weight using the acid method. Differential scanning calorimetry (DSC) results demonstrate that T_d (69.04 °C) of ASC was higher than T_d (62.20 °C) of PSC. Both ASC and PSC had the highest solubility at acidic pHs or at a low concentration of NaCl (<2%, w/v). The results of FTIR suggested the ASC and PSC maintained in the helical secondary structure at high degree.     

Isolation and characterization of acid soluble collagens and pepsin soluble collagens from the skin and bone of Spanish mackerel (Scomberomorous niphonius)

The objective of this study was to extract and characterize acid soluble collagens (ASCs) and pepsin soluble collagens (PSCs) from the skin and bone of Spanish mackerel (Scomberomorous niphonius) and to provide a simultaneous comparison of the four collagens. The yields of ASC-S (ASC from skin), PSC-S (PSC from skin), ASC-B (ASC from bone) and PSC-B (PSC from bone) were 13.68 ± 0.35, 3.49 ± 0.24, 12.54 ± 0.83 and 14.27 ± 0.66% (on wet weight basis), respectively. The four collagens contained glycine (341.6–352.6 residues/1000 residues) as the major amino acid and the contents of imino acids were between 177.1 and 184.3 residues/1000 residues. Amino acid composition, SDS-PAGE and FTIR confirmed that ASC-S, ASC-B and PSC-B were mainly composed of type I collagen with slight molecular structure differences, and PSCs had lower content of high-molecular weight cross-links than that of ASCs. The denaturation temperatures of ASC-S, PSC-S, ASC-B and PSC-B were 15.12, 14.66, 18.02 and 16.85 °C, respectively, which were much lower than those of collagens from the mammalian and tropical fish species due to low imino acid contents. All the collagens were soluble at acidic pH (1–4) and lost their solubility when the NaCl concentrations were above 2% (w/v). The four lyophilized collagens displayed a uniform and regular network ultrastructure based on the ultrastructural analysis. The isolated collagens from Spanish mackerel could serve as an alternative source of collagens for further application in food and neutraceutical industries.     

IgE reactivity to type I collagen and its subunits from tilapia (Tilapia zillii)

Acid-soluble collagen (ASC) was isolated from the skin of tilapia (Tilapia zillii) via acetic acid (HAc) extraction and NaCl precipitation. ASC from tilapia consists of α chains (α1 and α2), β chains and γ chains and is classified as type I collagen. A comparison of the properties of tilapia collagen and silver carp parvalbumin showed that tilapia collagen was less stable under heat treatment and more resistant to pepsin digestion. Both tilapia collagen and silver carp parvalbumin were degraded at pH 2.0 but stable at pH 3.0–11.0. Subunits α1 and α2 were further purified from tilapia collagen by carboxymethyl (CM) cellulose column chromatography with linear gradient elution and stepwise elution, respectively. Enzyme-linked immunosorbent assay (ELISA) and immunoblotting results demonstrated the specific IgE activity of different fish-allergenic patients’ sera towards the α1 and α2 chains of tilapia collagen. It can be inferred that tilapia collagen and its subunits are all potential allergens.