大豆蛋白添加量与成膜环境对大豆分离蛋白膜的影响

以大豆分离蛋白(SPI)为原料,通过调整SPI和甘油(GLY)的比例来制备不同配方的可食性SPI包装膜。通过观察薄膜色泽、柔软性等表观情况,测定其机械性能(抗拉强度和断裂伸长率)和阻隔性能(阻湿性和阻氧性),并比较了其性能。结果表明:影响SPI膜性能的主要因素为SPI添加量、SPI与增塑剂的质量比、干燥条件;在pH=9条件下,SPI质量为5.66 g,SPI与GLY质量比为6∶1.5,以自然晾干和烘箱干燥结合法进行干燥时,膜的性能最优。     

蛋白质药品冷冻干燥技术研究进展

冷冻干燥技术是制备固体蛋白质药品的常用方法。本文综述了蛋白质药品冻干保护机理、冻干工艺、冻干机的研究进展，并提出了优化药品冷冻干燥过程，提高药品的稳定性和经济性的研究思路。     

CSF－1R部分基因在大肠杆菌中表达、抗融合蛋白血清制备及丝氨酸／苏氨酸磷酸化的初步研究

鼠巨噬细胞集落刺激因子－１受体（ｍＣＳＦ－１Ｒ）部分序列与质粒ｐＧＥＸ－２Ｔ谷胱苷肽转移酶（ＧＳＴ）融合，融合蛋白ＧＳＴ－ＣＤ－Ｐｓｔ（胞浆区），ＧＳＴ－ＣＴｅｒｍ（Ｃ－末端）和ＧＳＴ－ＫＩ（激酶插入区）成功地在大肠杆菌ＪＭ１０９株表达。初步结果指出：（１）ＧＳＴ－融合蛋白在体外激酶分析中可以作为底物；（２）由ＰＫＡ导致的磷酸化可能具有生理学意义；（３）ｍＣＳＦ－１Ｒ被ＣＫＩＩ磷酸化。３２Ｐ标记ＧＳＴ－ＣＤ－Ｐｓｔ的磷酸氨基酸分析证实，ｍＣＳＦ－１Ｒ的胞浆区丝氨酸上被磷酸化，已制备抗ＧＳＴ－ＣＴｅｒｍ，ＧＳＴ－ＫＩ和ＧＳＴ－ＣＤ－Ｐｓｔ兔抗体。抗血清的筛选通过野生型３２Ｄ－ＣＳＦ－１Ｒ转染子免疫沉淀进行。     

The Potential Role of SP-G as Surface Tension Regulator in Tear Film: From Molecular Simulations to Experimental Observations

The ocular surface is in constant interaction with the environment and with numerous pathogens. Therefore, complex mechanisms such as a stable tear film and local immune defense mechanisms are required to protect the eye. This study describes the detection, characterization, and putative role of surfactant protein G (SP-G/SFTA2) with respect to wound healing and surface activity. Bioinformatic, biochemical, and immunological methods were combined to elucidate the role of SP-G in tear film. The results show the presence of SP-G in ocular surface tissues and tear film (TF). Increased expression of SP-G was demonstrated in TF of patients with dry eye disease (DED). Addition of recombinant SP-G in combination with lipids led to an accelerated wound healing of human corneal cells as well as to a reduction of TF surface tension. Molecular modeling of TF suggest that SP-G may regulate tear film surface tension and improve its stability through specific interactions with lipids components of the tear film. In conclusion, SP-G is an ocular surface protein with putative wound healing properties that can also reduce the surface tension of the tear film.     

Understanding the effects of various edible coatings on the storability of fresh cherry

n this work, cherries, which have a very short shelf life, were packaged after being coated with various edible coatings [whey protein isolate (WPI), chitosan and shellac]. The changes in gas composition, weight loss, Brix, pH, electrical conductivity and firmness were measured periodically up to 11 days after harvest to compare the effects of the applied coatings. Fourier transform near‐infrared (FT‐NIR) spectroscopymeasurements were also taken individually. After storage, the gas composition within trays was about 1–10% O₂ and 14–47% CO₂. The lowest weight loss (25.56%) was observed in the shellac‐coated cherries, while the highest loss (48.58%) occurred in the control group. Coated cherries exhibited a significantly lower pH and electrical conductivity than the uncoated ones. The control group presented the highest total soluble solid (TSS) values (21.29) and shellac coating had (17.25) the lowest. At the end of storage, the highest ascorbic acid (AA) content was 0.64 mg/100 ml in the shellac‐coated cherries, and the lowest AA content of 0.40 mg/100 ml was measured in the control group. Firmness was maintained by coating, especially with shellac (3.734 N), whereas the control had the lowest firmness measured (2.138 N) at the end of storage. There were differences between the absorbance spectra for the coated and control cherries at the end of storage. This research concludes that shellac coating is more effective in reducing the respiration rate and maintaining the quality parameters of cherries than chitosan and WPI coatings. Major benefits of coatings were observed in lessening the weight‐loss process and in maintaining firmness, which were also supported by the FT‐NIR measurements. Copyright © 2010 John Wiley & Sons, Ltd.     

Unraveling Membrane Perturbations Caused by the Bacterial Riboregulator Hfq

Hfq is a pleiotropic regulator that mediates several aspects of bacterial RNA metabolism. The protein notably regulates translation efficiency and RNA decay in Gram-negative bacteria, usually via its interaction with small regulatory RNAs. Previously, we showed that the Hfq C-terminal region forms an amyloid-like structure and that these fibrils interact with membranes. The immediate consequence of this interaction is a disruption of the membrane, but the effect on Hfq structure was unknown. To investigate details of the mechanism of interaction, the present work uses different in vitro biophysical approaches. We show that the Hfq C-terminal region influences membrane integrity and, conversely, that the membrane specifically affects the amyloid assembly. The reported effect of this bacterial master regulator on membrane integrity is discussed in light of the possible consequence on small regulatory RNA-based regulation.     

State-of-the-Art on Wound Vitality Evaluation: A Systematic Review

The vitality demonstration refers to determining if an injury has been caused ante- or post-mortem, while wound age means to evaluate how long a subject has survived after the infliction of an injury. Histology alone is not enough to prove the vitality of a lesion. Recently, immunohistochemistry, biochemistry, and molecular biology have been introduced in the field of lesions vitality and age demonstration. The study was conducted according to the preferred reporting items for systematic review (PRISMA) protocol. The search terms were “wound”, “lesion”, “vitality”, “evaluation”, “immunohistochemistry”, “proteins”, “electrolytes”, “mRNAs”, and “miRNAs” in the title, abstract, and keywords. This evaluation left 137 scientific papers. This review aimed to collect all the knowledge on vital wound demonstration and provide a temporal distribution of the methods currently available, in order to determine the age of lesions, thus helping forensic pathologists in finding a way through the tangled jungle of wound vitality evaluation.     

The Calcium-Dependent Protein Kinase TaCDPK27 Positively Regulates Salt Tolerance in Wheat

As essential calcium ion (Ca²⁺) sensors in plants, calcium-dependent protein kinases (CDPKs) function in regulating the environmental adaptation of plants. However, the response mechanism of CDPKs to salt stress is not well understood. In the current study, the wheat salt-responsive gene TaCDPK27 was identified. The open reading frame (ORF) of TaCDPK27 was 1875 bp, coding 624 amino acids. The predicted molecular weight and isoelectric point were 68.905 kDa and 5.6, respectively. TaCDPK27 has the closest relationship with subgroup III members of the CDPK family of rice. Increased expression of TaCDPK27 in wheat seedling roots and leaves was triggered by 150 mM NaCl treatment. TaCDPK27 was mainly located in the cytoplasm. After NaCl treatment, some of this protein was transferred to the membrane. The inhibitory effect of TaCDPK27 silencing on the growth of wheat seedlings was slight. After exposure to 150 mM NaCl for 6 days, the NaCl stress tolerance of TaCDPK27-silenced wheat seedlings was reduced, with shorter lengths of both roots and leaves compared with those of the control seedlings. Moreover, silencing of TaCDPK27 further promoted the generation of reactive oxygen species (ROS); reduced the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT); aggravated the injury to photosystem II (PS II); and increased programmed cell death (PCD) in wheat leaves under NaCl treatment, confirming that the TaCDPK27-silenced seedlings exhibited more NaCl injury than control seedlings. Taken together, the decrease in NaCl tolerance in TaCDPK27-silenced seedlings was due to excessive ROS accumulation and subsequent aggravation of the NaCl-induced PCD. TaCDPK27 may be essential for positively regulating salt tolerance in wheat seedlings.     

Protein–Protein Interaction Prediction for Targeted Protein Degradation

Protein–protein interactions (PPIs) play a fundamental role in various biological functions; thus, detecting PPI sites is essential for understanding diseases and developing new drugs. PPI prediction is of particular relevance for the development of drugs employing targeted protein degradation, as their efficacy relies on the formation of a stable ternary complex involving two proteins. However, experimental methods to detect PPI sites are both costly and time-intensive. In recent years, machine learning-based methods have been developed as screening tools. While they are computationally more efficient than traditional docking methods and thus allow rapid execution, these tools have so far primarily been based on sequence information, and they are therefore limited in their ability to address spatial requirements. In addition, they have to date not been applied to targeted protein degradation. Here, we present a new deep learning architecture based on the concept of graph representation learning that can predict interaction sites and interactions of proteins based on their surface representations. We demonstrate that our model reaches state-of-the-art performance using AUROC scores on the established MaSIF dataset. We furthermore introduce a new dataset with more diverse protein interactions and show that our model generalizes well to this new data. These generalization capabilities allow our model to predict the PPIs relevant for targeted protein degradation, which we show by demonstrating the high accuracy of our model for PPI prediction on the available ternary complex data. Our results suggest that PPI prediction models can be a valuable tool for screening protein pairs while developing new drugs for targeted protein degradation.