胶原蛋白肽红枣汁复合饮料的研制

目的以红鳍东方鲀鱼皮制得的胶原蛋白肽(1~5 ku)和红枣汁为原料研制胶原蛋白肽红枣汁复合饮料,并确定其最佳的生产工艺。方法以氮得率和感官评价为指标,通过单因素和正交试验研究脱腥时间、脱腥温度、活性炭添加量等3个因素对胶原蛋白肽脱腥效果的影响;以感官评价为指标,通过单因素和正交试验研究胶原蛋白肽和红枣汁的添加配比、蔗糖添加量、柠檬酸添加量对胶原蛋白肽红枣汁复合饮料风味、澄清度、香气、色泽的影响;以菌落总数和感官评价为指标,研究温度对胶原蛋白肽红枣汁复合饮料灭菌效果的影响。结果活性炭添加量为2.00 mg/mL,脱腥温度为45℃,脱腥时间为20 min,添加胶原蛋白肽和红枣汁的体积比为2:1,蔗糖的质量分数为2.50%,柠檬酸的质量分数为0.15%,在压力0.02 MPa,温度105℃条件下灭菌10 min时,感官评分最高,所制得的饮料酸甜可口、口感顺滑,具有浓郁的红枣香气和特有的胶原蛋白香气。结论适宜的活性炭添加量、脱腥温度、脱腥时间,蔗糖、柠檬酸添加量,胶原蛋白肽和红枣汁的添加配比,以及灭菌条件,可以最大限度地保留饮料的特有风味。     

ACE抑制肽研究进展

该文对目前国内外有关ACE抑制肽研究进展进行综述,重点介绍制备ACE抑制肽原料、分离提取方法、结构与活性关系、活性测定方法和功能性评价方法,并简介其在食品中应用及发展前景,以期为对ACE抑制肽进一步研究提供参考。     

干腌火腿抗氧化肽的研究进展

自由基过量累积会导致人体许多慢性疾病的产生,如衰老、慢性炎症、心血管疾病等,目前常规的解决方法是使用抗氧化剂。然而人工合成的抗氧化剂对人体有潜在危害,因此无毒副作用的抗氧化肽成为了当今研究的热点。作为发酵肉制品之一的干腌火腿,因其蛋白质含量丰富,且在发酵过程中受到内源酶和微生物的影响,会对蛋白质进行分解,从而产生具有抗氧化活性的小肽。大量的研究表明,来源于干腌火腿的肽具有极强的抗氧化活性。因此,干腌火腿作为天然抗氧化肽的潜在来源,备受研究人员的关注。本文综述了干腌火腿中抗氧化肽研究的最新进展,主要包括抗氧化肽的形成、制备、纯化鉴定及抗氧化机制4个方面,其中特别指出外源微生物对抗氧化肽形成的影响,以期为干腌火腿抗氧化肽的进一步研究提供理论基础。     

蛹酰化肽的合成

以生物技术酶解蛹蛋白、油酸、三氯化磷、氢氧化钠为原料,在微负压、碱性条件下,恒温４０℃,控速１０００ｒ／ｍｉｎ搅拌,滴加油酰氯反应２～３ｈ,合成了新型天然表面活性剂蛹酰化肽,并对其与进口日本产品质量进行了对比,蛹酰化肽相对分子质量为３０００～３５００,在日本产品质量标准２００～５０００的范围内,酰化总收率达７５０％。     

Screening of Novel Bioactive Peptides from Goat Casein: In Silico to In Vitro Validation

Food-derived bioactive peptides are of great interest to science and industry due to evolving drivers of food product innovation, including health and wellness. This study aims to draw attention through a critical study on how bioinformatics analysis is employed in the identification of bioactive peptides in the laboratory. An in silico analysis (PeptideRanker, BIOPEP, AHTpin, and mAHTPred) of a list of peptides from goat casein hydrolysate was performed to predict which sequences could potentially be bioactive. To validate the predictions, the in vitro antihypertensive potential of the five peptides with the highest potential was first measured. Then, for three of these, gastrointestinal digestion was simulated in vitro, followed by the analysis of the resulting ACE inhibitory activity as well as antioxidant capacity. We thus observed that the use of new computational biology technologies to predict peptide sequences is an important research tool, but they should not be used alone and complementarity with various in vitro and in vivo assays is essential.     

TAMpepK Suppresses Metastasis through the Elimination of M2-Like Tumor-Associated Macrophages in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) accounts for approximately 10–15% of all breast cancer cases and is characterized by high invasiveness, high metastatic potential, relapse proneness, and poor prognosis. M2-like tumor-associated macrophages (TAMs) contribute to tumorigenesis and are promising targets for inhibiting breast cancer metastasis. Therefore, we investigated whether melittin-conjugated pro-apoptotic peptide (TAMpepK) exerts therapeutic effects on breast cancer metastasis by targeting M2-like TAMs. TAMpepK is composed of M2-like TAM binding peptide (TAMpep) and pro-apoptotic peptide d(KLAKLAK)₂ (dKLA). A metastatic mouse model was constructed by injecting 4T1-luc2 cells either orthotopically or via tail vein injection, and tumor burden was quantified using a bioluminescence in vivo imaging system. We found that TAMpepK suppressed lung and lymph node metastases of breast cancer by eliminating M2-like TAMs without affecting the viability of M1-like macrophages and resident macrophages in the orthotopic model. Furthermore, TAMpepK reduced pulmonary seeding and the colonization of tumor cells in the tail vein injection model. The number of CD8⁺ T cells in contact with TAMs was significantly decreased in tumor nodules treated with TAMpepK, resulting in the functional activation of cytotoxic CD8⁺ T cells. Taken together, our findings suggest that TAMpepK could be a novel therapeutic agent for the inhibition of breast cancer metastasis by targeting M2-like TAMs.     

Design and Experimental Evaluation of a Peptide Antagonist against Amyloid β(1–42) Interactions with Calmodulin and Calbindin-D28k

Amyloid β_1–42 (Aβ(1–42)) oligomers have been linked to the pathogenesis of Alzheimer’s disease (AD). Intracellular calcium (Ca²⁺) homeostasis dysregulation with subsequent alterations of neuronal excitability has been proposed to mediate Aβ neurotoxicity in AD. The Ca²⁺ binding proteins calmodulin (CaM) and calbindin-D28k, whose expression levels are lowered in human AD brains, have relevant roles in neuronal survival and activity. In previous works, we have shown that CaM has a high affinity for Aβ(1–42) oligomers and extensively binds internalized Aβ(1–42) in neurons. In this work, we have designed a hydrophobic peptide of 10 amino acid residues: VFAFAMAFML (amidated-C-terminus amino acid) mimicking the interacting domain of CaM with Aβ (1–42), using a combined strategy based on the experimental results obtained for Aβ(1–42) binding to CaM and in silico docking analysis. The increase in the fluorescence intensity of Aβ(1–42) HiLyte^TM-Fluor555 has been used to monitor the kinetics of complex formation with CaM and with calbindin-D28k. The complexation between nanomolar concentrations of Aβ(1–42) and calbindin-D28k is also a novel finding reported in this work. We found that the synthetic peptide VFAFAMAFML (amidated-C-terminus amino acid) is a potent inhibitor of the formation of Aβ(1–42):CaM and of Aβ(1–42):calbindin-D28k complexes.     

The X-ray structure of (MeBm2t)1-cyclosporin complexed with cyclophilin A provides an explanation for its anomalously high immunosuppressive activity

For most of the cyclosporin A (CsA) analogs, there is generallya good correlation between cyclophilin binding and immunosuppression.However, this relationship does not seem to hold for 4-[(E)-2-butenyl]-4,4,N-trimethyl-L-threonine¹(MeBm₂t)¹-CsA.Its affinity for cyclophilin was reported to be {small tilde}1percent; that of CsA and its immunosuppressive activity invitro was shown to be {small tilde} 30% that of CsA. We reporthere the crystal structure of a complex between recombinanthuman cyclophilin A (CypA) and (MeBm₂t)¹-CsA which has beendetermined by X-ray crystallography at 2.2 Å resolutionand refined to an Rfactor of 16.3%. (MeBm₂t)¹-CsA shows a similarbound conformation and network of interactions to CypA as CsA.The measured lower affinity for CypA cannot therefore be explainedby a different mode of binding. We propose that the poor affinityto CypA could be accounted for by the existence of an equilibriumin aqueous solution between a ‘cyclophilin bound conformation’and a ‘nonbinding conformation’ of (MeBm₂t)¹-CsA.The relatively high immunosuppressive activity is suggestedto result from slight conformational differences observed inthe effector domain     

Synthesis and Application of Peptide Arrays: Quo Vadis SPOT Technology

Hitting the SPOT : In 1992, Ronald Frank published the first seminal paper on simultaneous parallel synthesis of multiple peptides on filter paper. He defined the approach as SPOT synthesis, an easy technique for positionally addressable, parallel chemical synthesis on a membrane support. Here, a basic overview of this technology is presented and a recently published applications are highlighted. At the end, the future of peptide arrays is discussed.