双蛋白凝胶的形成机理及其在食品加工中的应用

双蛋白作为理想的食品成分,在高蛋白食品配方中变得越来越具有吸引力。与单一的蛋白凝胶相比,双蛋白凝胶具有更好的质地特性、持水性和热稳定性,其凝胶特性的增强机制主要归因于蛋白质之间增加的链缠结、非共价相互作用以及亲水基团和水之间的相互作用。文章总结了双蛋白凝胶的制备方法、形成机理、理化特性以及在食品加工中的应用进展,并展望了双蛋白凝胶在食品领域的应用前景,旨在为双蛋白新型营养健康产品的开发应用提供参考。

HSP27:a candidate differentially expressed protein between left-and right-sided colon carcinomas

Objective:The aim of the study was to screen differentially expressed proteins between left-and right-sided colon cancers by proteomics techniques and provide molecular genetic basis for oncobiological difference between left-and rightsided colon cancers.Methods:Tissue samples including left-and right-sided colon cancers were collected and preserved in the-80 ℃ refrigeratory.In the first part of our experiment,protein separating was performed by using two-dimensional gel electrophoresis(2-DE) and the images of the gels were acquired by the scanner and then analyzed to find the differentially expression protein-spots in different groups.The peptide mass fingerprintings(PMF) was acquired by matrix assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS) and the proteins were identified by data searching in the Mascot-database.Differentially expression proteins were assayed by RT-PCR,Western blot,and immunohistochemical methods.Results:The 55 differentially expressed protein spots were screened and 23 spots of them were identified.Compared to right-sided colon cancer,15 proteins up-regulated and 8 proteins down-regulated including HSP27 in left-sided colon cancer.HSP27 expressed higher in right-sided than in left-sided colon cancers by RT-PCR,Western blot and immunohistochemical methods.Conclusion:There were differentially expressed proteins between left-and right-sided colon cancers,especially differences in HSP27 expression in mRNA and protein level,which were molecular genetic basis for oncobiological difference between left-and right-sided colon cancers.

Comparative proteomic study of cervical cancer with different radiotherapy sensitivity

Objective： To investigate the proteornic differences between the high-sensitivity （HS） group and low-sensitivity （LS） group of cervical cancer treated by radiotherapy and confirm the radiotherapy sensitivity associated proteins in early cervical cancer. Methods： The fresh carcinoma tissues were collected from 10 untreated cervical cancer patients and preserved in the -80 ℃ refrigeratory. The tissues were classified into two groups： high sensitivity group （HS） and low sensitivity group （LS）, according to their response to radiotherapy. In the first part of our experiment, protein separating was performed by using two-dimensional gel electrophoresis （2-DE） with Amersham 18 cm linear pH 3-10 immobilized pH gradient （IPG） strips. The images of the gels were acquired by the scanner and then analyzed by using PD-quest7.3 software to find the differentially expression protein-spots in each group. Then the differentially expressed protein-spots was incised from the gels and digested by trypsin. The peptide mass fingerprintings （PMF） was acquired by matrix assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） and the proteins were identified by data searching in the Mascot-database. Part of differentially expression proteins were assayed by Western Blot. Results： Most of the gels were clear and successfully analyzed by PD-quest7.3 software. Most of the protein-spots concentrated on the area of 20-100Kda （Mw） and pH4-8. The average number of the protein-spots was 754 ± 64 in HS group and 777 ±48个 in LS group. The match rate was 87.6% between two groups. Five high expression proteins were found in HS group which were low expression in LS group, 3 high expression protein were found in LS group which were low expression in HS group. Reselts of Western Blot were in coincidence to proteomic result. Conclusion： The 2-DE gels image of HS group and LS group with early cervical cancer tissues treated by radiotherapy are successfully acquired. Some differentially expression proteins between the two groups are further confirmed by immunohistochemical assay.

Preparation and evaluation of enzyme encapsulated hydrogels(single gels and double network gels) and enzyme immobilized magnetic beads

In the present research,enzyme encapsulated hydrogels（single gels and double network gels）and enzyme immobilized magnetic beads,which allow high-throughput screening,were fabricated and evaluated in terms of the preservation,precision, and repeatability of enzyme activity.The fabricated gels and magnetic beads were analyzed in a 96-well microassay plate.Trypsin was successfully encapsulated in both types of gels and immobilized to the magnetic beads.However,pepsin,either encapsulated in the gels or immobilized to the magnetic beads,could not react with its substrates.The adaptability to various enzymes （e.g.,trypsin,β-glucuronidase,and CYP1A1）in the single gels and magnetic beads was superior to that in double network gels.However,the soak out of the enzymes was observed in the single gels.The double network gels could encapsulate trypsin,whereas the fabrication of the other enzymes（e.g.β-glucuronidase,CYP1A1,and pepsin）failed because of the inactivation of the enzymes by acryl amide and ammonium peroxodisulfate,which are the components of the gel formulation. The enzyme reaction in the magnetic beads exhibited the highest efficiency among the three fabrication methods.Furthermore, the stability of the enzymes immobilized to the magnetic beads was better than that fabricated by the other methods,and the activities of trypsin andβ-glucuronidase did not decline for up to one week.In addition,in the magnetic beads,the activities of trypsin andβ-glucuronidase can be well repeated.Hence,although the adaptability of the double network gels to various enzymes is currently limited,the efficiency of the enzyme encapsulation can be improved by optimizing the formulation of acryl amide gels.