鹿骨胶原蛋白特性的研究

采用酸和酶提取法从鹿骨中提取酸溶性胶原蛋白（ASC）和胃蛋白酶促溶性胶原蛋白（PSC）,利用紫外扫描、傅立叶变换红外光谱、DSC、SDS-PAGE垂直电泳和氨基酸分析仪,研究了鹿骨胶原蛋白的结构、热收缩温度、相对分子量和氨基酸组成。结果表明：紫外扫描分析,鹿骨的ASC和PSC在234nm处均有强烈吸收,具有胶原蛋白的特性;红外光谱说明胶原纤维保留了大量的三股螺旋结构;经DSC测定,鹿骨的ASC和PSC热收缩温度分别为55℃和58℃。SDS-PAGE电泳显示,胶原蛋白含有3条不同的链,α1、α2和β链。氨基酸分析表明,具有典型胶原蛋白的氨基酸组成。     

人工养殖大鲵皮胶原蛋白的性质研究

在低温4 ℃条件下,采用酸法（0.5 mol/L乙酸）和酶法（胃蛋白酶）对人工养殖大鲵皮中的胶原蛋白进行了提取,对提取纯化后的两种不同类型的胶原蛋白--酸溶性胶原蛋白（acid-soluble collagen,ASC）和胃蛋白酶酶促溶性胶原蛋白（pepsin-soluble collagen,PSC）其各项理化性质进行了研究。结果表明：ASC和PSC均包含2 条α链及它们的二聚体β链,为Ⅰ型胶原蛋白;ASC和PSC中甘氨酸含量最高,其次为谷氨酸和脯氨酸,胱氨酸含量最低;ASC和PSC中亚氨基酸含量分别为144和173（以残基/1 000残基计）,两者热变性温度分别为23.5 ℃和26.5 ℃,表明PSC的热稳定性较优;ASC和PSC的紫外最大吸收峰分别位于233.0 nm和232.0 nm波长处,符合胶原蛋白的特征;ASC和PSC的红外特征吸收频率相似,均含有酰胺Ⅱ带、酰胺Ⅲ带及在两酰胺带间的一系列吸收峰,表明ASC和PSC中胶原蛋白的三螺旋结构较为完整。     

胶原蛋白的提取及其纳米纤维的制备与表征

为提高羊皮中胶原蛋白的提取率和利用率，采用酸酶复合法提取羊皮胶原蛋白，再利用静电纺技术制备胶原基纳米纤维。以羊皮胶原蛋白提取率为评价指标，考察料液比、乙酸浓度、胃蛋白酶浓度和酶解时间四个因素对羊皮胶原蛋白提取效果的影响，确定单因素最优水平；在此基础上，采用正交试验设计对羊皮胶原蛋白提取的工艺条件进行优化，并通过紫外光谱扫描、红外光谱扫描、SDS-PAGE图谱和扫描电镜等生化技术探讨酶解过程对胶原蛋白结构性质的影响；然后将胶原蛋白和聚乳酸复合静电纺丝，制备得到胶原基纳米纤维。结果表明，酸酶复合法提取羊皮胶原蛋白最佳工艺为：料液比1:25 g/mL、乙酸浓度1.2 mol/L、胃蛋白酶用量1.0%、酶解时间72 h，在此条件下羊皮胶原蛋白提取率为38.42%±0.49%；紫外光谱扫描显示羊皮胶原蛋白于230 nm附近出现最大紫外吸收峰；红外光谱扫描、SDS-PAGE图谱分析表明羊皮胶原蛋白主要有α₁、α₂、β三种亚基成分组成，属于Ⅰ型胶原蛋白，且胶原蛋白的空间结构保留完整；扫描电镜直观表明了羊皮胶原蛋白的纤维网络结构保留较完整；静电纺丝得到的胶原...     

不同提取方法对东北林蛙皮胶原蛋白理化特性的影响

以东北林蛙皮为原材料,用乙酸和胃蛋白酶两种方法对其中所含的胶原蛋白进行提取,最终得到两种胶原蛋白:酸溶性胶原蛋白(ASC)和酶溶性胶原蛋白(PSC),并对这两种胶原蛋白的理化性质及功能特性进行比较研究。结果发现,ASC和PSC在234 nm附近都有强吸收峰,符合胶原蛋白的特征;红外光谱发现ASC在3346.0、2952.0、1662.0、1548.0、1242.0 cm~(-1)有吸收峰,PSC在3322.0、2944.0、1662.0、1551.0、1236.0 cm~(-1)有吸收峰,证明这两种胶原蛋白都存在酰胺A、酰胺B、酰胺Ⅰ、酰胺Ⅱ、酰胺Ⅲ,内部三螺旋结构都保留完整;氨基酸组成表明ASC和PSC都含有18种氨基酸,包括人体所需的8种必需氨基酸,但是组成略有差异;SDS-PAGE电泳结果显示,这两种胶原蛋白都存在β、α1和α2链,符合Ⅰ型胶原蛋白的结构特征;PSC的变性温度较ASC要高,但是保湿率较低,它们的吸湿率和相对溶解度差异不显著(p0.05);以上结果表明不同提取方法对东北林蛙皮胶原蛋白的结构、功能特性有一定影响,但是不影响胶原蛋白的品质。     

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。     

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℃.     

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。     

酸法和酶法提取草鱼鱼鳞胶原蛋白的特性分析

以草鱼鱼鳞为原料,分别采用酸法和酶法提取胶原蛋白并进行理化性质分析。通过氨基酸组成、紫外光谱、傅里叶红外光谱、聚丙烯酰胺凝胶电泳(SDS-PAGE)、变性温度,对胶原蛋白进行比较。结果表明,2种方法的提取物均为典型的胶原蛋白,在波长230 nm左右出现最大紫外吸收峰;红外光谱及SDS-PAGE凝胶电泳显示提取的ASC和PSC主体结构一致,属于Ⅰ型胶原蛋白,胃蛋白酶不会破坏胶蛋白三螺旋构象,酸溶胶原蛋白和酶溶胶原蛋白的热变性分别为30.16℃和30.63℃。综合来看2种方法所提胶原蛋白在理化特性上并无太大差别,可以利用胃蛋白酶处理有效提高胶原蛋白的提取率。     

酸法和酶法提取牦牛骨胶原蛋白的特性分析

以牦牛骨为原料,分别采用酸法和酶法提取胶原蛋白并进行理化性质分析。通过氨基酸组成、紫外光谱、傅里叶变换红外光谱、热收缩温度、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecyl sulfate-polyacrylamide gelelectrophoresis,SDS-PAGE）和扫描电子显微镜图像分析对胶原蛋白进行比较。结果表明：2?种方法的提取物都为典型的胶原蛋白,在230?nm波长左右出现最大紫外吸收峰;酸溶胶原蛋白（acid-soluble collagen,ASC）和酶溶胶原蛋白（pepsin-soluble collagen,PSC）的热收缩温度分别为40.12?℃和40.94?℃,变性焓值分别为0.25?J/g和0.22?J/g;红外光谱及SDS-PAGE分析表明,ASC和PSC主要由α、β、γ三种亚基组分组成,属于I型胶原蛋白,且三股螺旋结构完整;扫描电子显微镜结果表明,2?种方法提取的胶原蛋白都保留了较为完整的纤维网状结构,但酸法提取的胶原蛋白结构分布相对均匀。综合来看,2?种方法所提胶原蛋白在理化特性上并无太大差别,但酶法提取的胶原蛋白得率较高,酸法提取成本较低。     

不同方法提取沙海蜇皮胶原蛋白的对比分析

以沙海蜇皮为实验原料,分别用胃蛋白酶提取法、热水提取法和酸提取法进行了胶原蛋白的提取,得到酶溶性胶原蛋白(PSC)、热水抽提胶原蛋白(HEG)和酸溶性胶原蛋白(ASC),并分析了三种胶原蛋白的理化性质及功能特性。结果表明:PSC、HEG和ASC中羟脯氨酸含量分别为5.77%,5.53%和9.20%;平均分子量分别为34、52、38ku。紫外图谱扫描和红外扫描光谱表明,三种方法提取的胶原蛋白结构相似,但略有差别。PSC、HEG、ASC乳化指数依次为:5.07、25.90、3.26m2/g;稳定性依次为:24.68、21.89、88.5min。吸湿性和保湿性最好的样品均为PSC。     

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.     

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     

Characteristics of acid soluble collagen and pepsin soluble collagen from scale of spotted golden goatfish (Parupeneus heptacanthus)

Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were extracted from scale of spotted golden goatfish (Parupeneus heptacanthus) with the yields of 0.46% and 1.20% (based on dry weight basis), respectively. Both ASC and PSC were characterised as type I collagen, containing α₁ and α₂ chains. β and γ components were also found in both collagens. Based on FTIR spectra, the limited digestion by pepsin did not disrupt the triple helical structure of collagen. ASC and PSC contained glycine (336–340 residues/1000 residues) as the major amino acid and had imino acids of 186–189 residues/1000 residues. Maximal transition temperatures (T_max) were 41.58 and 41.01 °C for ASC and PSC, respectively. From zeta potential analysis, net charge of zero was found at pH 4.96 and 5.39 for ASC and PSC, respectively. Both collagens exhibited high solubility in acidic pH (2–4) and were soluble in the presence of NaCl at concentration up to 20 and 30 g/l for ASC and PSC, respectively.     

Study on the self‐assembly property of type I collagen prepared from tilapia (Oreochromis niloticus) skin by different extraction methods

Type I collagen was prepared from tilapia (Oreochromis niloticus) skin by acetic acid and pepsin process at 4 °C, respectively (ASC and PSC), and hot‐water method separately at 25, 35 and 45 °C (C‐25, C‐35 and C‐45). Their structure and self‐assembly property were discussed. SDS‐PAGE patterns suggested that pepsin hydrolysis and the 35 and 45 °C extraction produced collagen with much reduced proportions of α‐ and β‐chains. Fourier transform infrared spectroscopy spectra revealed that pepsin hydrolysis did not change the conformation of collagen, but higher extraction temperature did. Self‐assembly curves and atomic force microscopy (AFM) observations showed that only ASC, PSC and C‐25 could self‐assemble into fibrils with D‐periodicity, but the reconstruction rate of C‐25 was lower. Besides, PSC had relatively higher resolution ratio compared with others. Overall, pepsin‐extracted collagen displayed higher solubility and better fibril‐forming capacity, having the potential of applying in biomaterials and food‐packaging materials.     

草鱼鱼鳞中活性胶原蛋白提取工艺及参数优化

以草鱼鱼鳞为原料,在低于蛋白变性温度的条件下提取酸溶性胶原蛋白(ASC)和酶溶性胶原蛋白(PSC),并对鱼鳞原料的前处理方法、胶原蛋白提取工艺进行优化。结果表明,在鱼鳞原料的前处理工艺中,以0.1mol/L 的Na2CO3 溶液为试剂脱除原料中杂蛋白的最佳工艺条件为室温、料液比1:40(g/mL),300r/min 搅拌处理3 次,每次6h;以0.3mol/L 的EDTA 为试剂脱除原料中矿物质杂质的最佳工艺条件为室温、料液比1:60,搅拌处理3 次,每次12h;ASC 的最佳提取工艺条件为：提取温度不高于25℃,料液比1:60,醋酸浓度0.8mol/L,提取3 次,每次24h;PSC 的最佳提取工艺条件为：胃蛋白酶用量为鱼鳞原料质量的3.0%、醋酸浓度0.8mol/L、料液比1:30、提取温度4 ℃、提取2 次,每次24h。     

Isolation and characterization of collagen from bigeye snapper (Priacanthus macracanthus) skin

Acid‐solubilized collagen (ASC) and pepsin‐solubilized collagen (PSC) were isolated from the skin of bigeye snapper (Priacanthus macracanthus) with yields of 64 and 11 g kg^?1 wet weight, respectively. Both ASC and PSC were characterized as type I collagens with no disulfide bonds. Peptide maps of ASC and PSC digested by V8 protease and lysyl endopeptidase showed some differences in peptide patterns and were totally different from those of calf skin collagen. The maximum solubility was observed at pH 4 and 5 for ASC and PSC, respectively. A sharp decrease in solubility of both collagens in acetic acid was found with NaCl concentration above 30 g l^?1. Thermal transitions of ASC and PSC in deionized water were observed with T_max of 30.37 and 30.87 °C, respectively, and were lowered in the presence of acetic acid (0.05 mol kg^?1 solution). Therefore, ASC was a major fraction in bigeye snapper skin and it exhibited some different characteristics to PSC. Copyright © 2005 Society of Chemical Industry     

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.     

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.