谷氨酰胺转氨酶催化蛋白质糖基化的研究进展

谷氨酰胺转氨酶(TGase)作为生物催化剂,催化蛋白质中γ-谷氨酰胺残基与带有伯氨的糖共价结合,从而改善蛋白的功能特性,减少美拉德反应中副产物的形成。综述了谷氨酰胺转氨酶酶促糖基化的反应机理、作用形式及其产物在食品中的应用,并对谷氨酰胺转氨酶催化蛋白质糖基化的发展前景进行了展望。     

谷氨酰胺转氨酶在豆渣制品中的应用

研究利用谷氨酰胺转氨酶对蛋白质的交联作用,通过调整大豆分离蛋白和豆渣的含量比及水分含量,对产品的感官品质进行改良。研究结果表明,添加适量的TG可以提高产品的弹性,改善其成形性和食用品质。对于水分含量为20%的湿豆渣,最佳作用条件为:大豆分离蛋白和湿豆渣的质量比为1:1,谷氨酰胺转氨酶应占成品质量的4%～5%,加水量占成品质量的70%～75%,水浴时间为0.5h,作用温度为90℃。     

谷氨酰胺转氨酶及其在食品工业上的应用研究进展

谷氨酰胺转氨酶（Transglutaminase, EC 2.3.2.13,TGase）是一种可催化蛋白质间形成异肽键使蛋白质改性的天然酶制剂。该酶可以催化蛋白质发生交联、脱酰胺和糖基化反应,在改善食品的硬度、粘性、弹性和持水力等方面具有较大的应用潜力。它的交联性可应用于:制造奶酪和其他乳制品、肉制品加工、生产可食性薄膜及微胶囊等。本文综述了TGase的分子结构、作用机理以及近年来国内外利用该酶在食品工业中改善食品品质的研究进展,以期为TGase在改善蛋白质功能性质、提升食品品质等方面的研究工作提供有效参考。     

谷氨酰胺转氨酶对面条水分状态及蛋白质结构的影响

利用核磁共振和傅里叶变换红外光谱技术,研究面条中水分分布和蛋白质结构参数的变化分析谷氨酰胺转氨酶(TG)的作用机理,并采用差示扫描量热仪、质构仪和感官评定研究面条的品质变化,确定其最适添加量。结果表明:谷氨酰胺转氨酶可降低面条的T_2弛豫时间,在0%~2.5%范围内,T_(21)和T_(22)呈现先减小后增大的趋势;面条体系中β-折叠片层和β-折叠的含量显著增加,α-螺旋和β-转角含量显著减小;显著提高面团糊化温度和热焓值,增强面条体系的热稳定性;影响面条的质构和感官品质,增加面条的硬度、弹性、内聚性和咀嚼性,添加量为1.5%时面条的品质最好。谷氨酰胺转氨酶可催化面筋蛋白分子交联和酰基转移反应,从而改变面条的水分分布、蛋白质结构及品质特点。     

毛细管电泳在蛋白质及其水解产物分析中的应用及进展

蛋白质是人体所有细胞和组织的重要成分,由氨基酸通过脱水缩合组成的多肽链经过盘曲折叠而构成。由于蛋白种类多且结构复杂,传统方法很难对其进行分离分析,电泳方法由此诞生。毛细管电泳是一种将电泳和色谱有机结合的快速分离技术。本文针对食品和药品领域,对毛细管电泳在蛋白质及其水解产物分析中的最新应用及研究进展进行了综述,主要从毛细管电泳的基本原理及主要类型、毛细管电泳与其他技术的联用及应用现状、毛细管电泳在食品和药品中蛋白质及其水解产物的分析应用方面进行了阐述和总结,并展望了毛细管电泳技术在特殊医学用途配方食品中蛋白质和多肽分子量测定方面的发展前景,以期为特殊医学用途配方食品中整蛋白及多肽分子量分布测定方法的开发提供参考。     

棉籽蛋白在天冬氨酸转氨酶发酵制备中的应用

进行了以棉籽蛋白替代蛋白胨和玉米浆的研究 ,培养大肠杆菌生产该酶 ,并对替代前后的酶活进行对比 ,确定了最佳培养基组成及发酵条件。研究表明 ,棉籽蛋白PM8成功替代原常规复合氮源后 ,培养基成本降低了4 0 %左右 ,发酵周期缩短了 2 5 % ,而L 苯丙氨酸的得率反而提高了 5 %。     

蛋白质氧化和翻译后修饰对肉品质的影响及机制研究进展

动物屠宰后,肌肉向可食肉转变的过程中涉及一系列的生化变化,它们相互影响并决定了肉的品质.其中氧化应激引起的蛋白质氧化以及蛋白质翻译后修饰对肉品质的形成具有重要影响,但鲜见对其机理系统的深入总结报道.本文综述了氧化应激与蛋白质氧化的关系,总结了动物屠宰后蛋白质氧化和翻译后修饰对肉的嫩度、持水性、肉色和营养价值等品质形成的...     

谷氨酰胺转氨酶在发酵乳制品中的应用研究进展

谷氨酰胺转氨酶(Transglutaminase, TG酶)是一种可催化蛋白质间形成异肽键使蛋白质改性的天然酶制剂。该酶可以催化蛋白质发生交联、脱酰胺和糖基化反应,在改善发酵乳制品的黏度、持水力、质构与凝胶特性等方面具有较大的应用潜力。文章论述了TG酶的作用机制、来源以及近年来国内外利用TG酶改善发酵乳品质的研究进展,以期为TG酶的工业化应用及发酵乳的品质改良提供有效参考。     

茂原链霉菌谷氨酰胺转氨酶在酸奶中的应用研究

为了研究本实验室制备的谷氨酰胺转氨酶(TGase)的应用特性,采用两种不同的TGase添加工艺生产酸奶:第一种采用TGase交联乳后加热钝化酶活力,然后添加发酵剂制备酸奶;第二种采用活性TGase与发酵剂同时添加到乳中的方法生产酸奶。通过对比这两种酸奶和对照样品(未添加TGase)的发酵时间、质构变化、乳清析出量和感官评价,确定此酶在酸奶中的添加条件。结果发现活性TGase交联酸奶的坚实度、粘度、乳清析出量和感官评价都有很大的改善,并且确定此TGase最适添加量为30U/L。     

蛋白质芯片在蛋白质组分离分析中的应用

目的介绍及评价蛋白质芯片技术在蛋白质组分离分析中的应用。方法综述近年来国内外相关文献。结果蛋白质芯片作为一种新型蛋白质分离分析技术,在受体-配体反应的检测、筛选药物以及评价药物效能和毒性等方面具有巨大的应用前景。结论蛋白质芯片技术是一种高通量、高灵敏度、高精度的技术平台,必将获得长足发展和广泛应用     

Gelation of Food Protein Induced by Recombinant Microbial Transglutaminase

ABSTRACT: The recombinant microbial transglutaminase from Streptoverticillium mobaraense var. (rMTGase) was expressed in Escherichia coli. Specific enzyme activity of rMTGase was comparable to native MTGase. However, the gelation of a sodium caseinate solution induced by rMTGase was slower than that induced by native MTGase. In addition, the mechanical property of kamaboko prepared with rMTGase was weaker than that with native MTGase. In SDS‐PAGE analysis, α‐casein monomers decreased more slowly during the incubation with rMTGase than MTGase. These results confirmed the difference of cross‐linking activity between the 2 enzymes. Furthermore, thermal stability of rMTGase was lower compared to native MTGase. These results suggest that the difference of cross‐linking activity and thermal stability between the 2 enzymes cause differences in gelation activity of protein.     

微生物发酵生产谷氨酰胺转胺酶的研究进展

简要介绍微生物发酵法生产谷氨酰胺转胺酶的国内外研究现状。     

谷氨酰胺转胺酶诱导交联发酵乳蛋白的体内抗氧化功效

为了研究微生物谷氨酰胺转胺酶诱导交联发酵乳蛋白(Microbial Transglutaminase CrossLinked Fermentation Milk Protein,m TG-FPM)对D-半乳糖(D-gal)衰老模型小鼠的抗氧化活性的影响,试验设正常组、D-gal模型组、D-gal+0Um TG-FPM组、D-gal+1Um TG-FPM组、D-gal+3Um TG-FPM组和D-gal+VE阳性对照组共6组,每组10只C57BL/J小鼠。采用皮下连续注射D-Gal方式建立衰老小鼠模型。造模同时,FPM各组每天灌服1.5 g/kg m TG-FPM/FPM,D-gal+VE阳性对照组每天灌服100 mg/kg的VE,模型对照和正常组每天灌服蒸馏水0.2 m L/10 g。连续灌胃8 w后,测定各组小鼠肝肾组织和血清中的相关抗氧化指标(CAT、SOD、GSH-Px MDA)。结果表明:D-Gal可显著降低衰老模型小鼠肝脏和血清中CAT及GSH-Px活性(P0.01,P0.05);显著降低肾脏和血清中的SOD活力(P0.01,P0.05),显著升高MDA含量(P0.01)。与模型组和0Um TG组相比,3Um TG组的肝脏CAT,1Um TG组血清CAT活性和3U m TG组肝脏GSH-Px活性显著升高(比0Um TG组分别升高11.14%、35.57%和22.36%,P0.01,P0.05);而3Um TG组肾脏中的MDA含量显著降低(比0Um TG组降低26.41%,P0.05)。因此,m TG诱导交联处理可在一定程度上改善FPM的体内抗氧化活性。     

Use of Soy Protein and Microbial Transglutaminase as a Binder in Low-sodium Restructured Meats

ABSTRACT: Pork sticks were prepared by mixing pork chucks with various amounts of bisulfite-treated soy protein and microbial transglutaminase (MTGase) to evaluate the potential of using soy protein as meat binders. According to tensile strength, the favorable conditions for binding the restructured pork chunks were 5% soy protein containing 0.2% NaHSO₃ and 20 unit MTGase/g, and the setting condition was 60 min at 40°C. The tensile strength and cooking yield of restructured pork sticks made with bisulfite-treated soy protein and MTGase were much higher than those of using salt, suggesting the high potential of using soy protein and MTGase as binders in products where NaCl reduction is desired.     

Strength of Protein Gels Prepared with Microbial Transglutaminase as Related to Reaction Conditions

Influence of gelling reaction conditions on the strength of several protein gels prepared with microbial transglutaminase (TGase) was investigated. A method was developed to gel proteins and measure gel breaking strength in a micro well plate. Enzyme concentration range for maximum gel breaking strength varied from 10 to 40 units/g protein. Maxima gel breaking strengths were achieved at 50°C for SPI, caseinate and gelatin and 65°C for egg yolk and egg white proteins. Optimum pH resulting in strong gels was pH 9 for SPI, caseinate, and egg yolk, and pH 6 for gelatin and egg white. Adjusting pH was promoted in egg white the formation of ?-(γ-glutamyl)lysine crosslinks and increased its gel breaking strength.     

Characteristics of Sodium Caseinate- and Soy Protein Isolate-Stabilized Emulsion-Gels Formed by Microbial Transglutaminase

ABSTRACT:  Protein-stabilized emulsion gels were prepared via microbial transglutaminase (mTGase) catalysis, and their physicochemical characteristics were examined. Emulsion oil droplet size and interfacial protein load were measured. The sodium caseinate and soy protein isolate emulsion gels exhibited different microstructures and physical properties. The emulsion gels improved the storage stability of aroma compounds. Rheological measurements of the emulsion gels revealed interesting strength, gelation kinetics, and thermal sensitivity properties. The mTGase-induced emulsion gels comprised a fine network which led to less release of aroma compounds upon storage than did emulsions. These results suggest that emulsion gels may be used to improve the texture of food emulsions and to control release of food aromas.     

谷氨酰胺转胺酶的性质及在食品中的应用

谷氨酰胺转胺酶是一种催化酰基转移反应的转移酶,它可使酪蛋白、肌球蛋白、谷蛋白和乳球蛋白等蛋白质分子之间产生交联,从而改变食品蛋白质的功能性质。本论述了谷氨酰胺转胺酶的性质及在食品开发中的应用。     

Assessment of Cross-Linking in Combined Cross-Linked Soy Protein Isolate Gels by Microbial Transglutaminase and Maillard Reaction

ABSTRACT:  Soy protein isolate (SPI) gels were produced using single cross-linking agents (SCLA) of microbial transglutaminase (MTG) via incubation for 5 or 24 h (SCLA-MTG). When powdered SCLA-MTG gels were heated for 2 h with ribose (R2) (2 g/100 mL), dark brown gels were formed, and these were designated as combined cross-linking agent (CCLA) gels: MTG5(R2) and MTG24(R2). The results showed that the levels of Maillard-derived browning and cross-links of MTG5(R2) and MTG24(R2) gels were significantly ( P  < 0.05) lower than a control gel produced without MTG (SCLA-R2) even though the percentage of ribose remaining after heating of these gels was similar, indicating that a similar amount of ribose was consumed during heating. ɛ-(γ-glutamyl)lysine bonds formed during incubation of SPI with MTG may have reduced the free amino group of SPI to take part in the Maillard reaction; nevertheless, ribose took part in the Maillard reaction and initiated the Maillard cross-linkings within the CCLA gels.     

谷氨酰胺转氨酶对大豆分离蛋白塑料拉伸性能的影响

研究了微生物谷氨酰氨转胺酶对大豆分离蛋白塑料拉伸性能的影响,发现在50℃时转氨酶对大豆分离蛋白催化聚合反应60 min,形成的高分子聚合物使大豆分离蛋白的抗拉强度和杨氏模量分别由未经处理时的9.2 MPa和265.4 MPa增加到14.7 MPa和390.1 MPa,同时增加了蛋白质的变性温度和热焓值。在酶处理90 min时,由于转氨酶变性失去活性及大豆分离蛋白的部分变性,蛋白质塑料的拉伸性能反而下降。对大豆分离蛋白的预热处理降低了转氨酶的催化聚合反应,且变性后的大豆分离蛋白制备的塑料拉伸性能大大降低。     

微生物谷氨酰胺转胺酶的应用进展

谷氨酰胺转胺酶是一种催化酰基转移反应的转移酶,它可使酪蛋白、肌球蛋白、谷蛋白和乳球蛋白等分子之间产生交联,改变蛋白质的功能性质,简述了谷氨酰胺转胺酶在食品应用的一些最新进展。