Optimization of Two-Dimensional Gel Electrophoresis for Kenaf Leaf Proteins

To establish a suitable and effective protocol of protein extraction for two-dimensional gel electrophoresis （2-DE） analysis in kenaf leaf tissues, three extraction methods （trichloroacetic acid/acetone, urea/thiourea, and phenol extraction methods） were applied to the extraction of kenaf leaf protein. The results were compared in regard to protein extraction efficiency, sodiumdodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）, and 2-DE gels. Furthermore, the 2-DE system was optimized for four aspects： the pH range of IPG （immobilized pH gradient） stripes, sampling methods, sample volumes, and concentration of polyacrylamide gels. The data presented showed that the phenol extraction method is the best method to perform 2-DE analysis of kenaf leaf protein. The protein extracted from phenol extraction method reached the purity of （26.40±0.859）%, showed （25.67±1.53） protein bands in one dimension SDS-PAGE gels, and （1 374±54.44） protein spots on 2-DE gels. The research also indicates that kenaf leaf protein spots were distributed mainly within the pH range of 4-8. More clear background with a better distribution effect and many protein spots could be obtained on 2-DE gels under the conditions of active rehydration loading, 24 cm IPG strips （linear pH gradient of 4-7）, 1.4 mg samples, and 12% SDS-PAGE gels.

Analysis of Sperm Membrane Protein Relevant to Antisperm Antibody by Two-Dimensional Gel Electrophoresis and Western Blotting

Objective To identify the sperm membrane proteins that are associated with antisperm antibody Methods Using antisperm antibody positive serum through unidimensional polyacrylamide gel electrophoresis and 2-dimensional gel electrophoresis followed by Western blot analysis to determine the molecular weights (MW) and isoelectric points (pI) of sperm membrane proteins that are associated with antisperm antibody. Results Eight kinds of MW with more than ten sperm membrane proteins can be recognized by antisperm antibody positive serum, of which the MWs and pI were 23 kD, 31 kD, 32 kD, 34 kD, 41 kD, 51 kD, 60 kD, 78 kD and 5.3, 5.5,5.7, 5.0, 5.3, 5.8, 6.0, 5.5～6.2, 4.6,5.1,5.5～5.8 respectively. The identification ratios of the sperm membrane proteins on 78 kD (60.7%), 60 kD (71.4%), 51 kD (14.9%) and 23 kD (14.29%) were higher. Conclusion The sperm membrane proteins with MW of 78 kD, 60 kD, 51 kD and 23 kD were associated with antisperm antibody and immunological infertility. Two- dimensional gel electrophoresis and Western blotting can precisely identify the sperm membrane proteins that are associated with antisperm antibody.

Comparative Proteomic Analysis of B. henselae Houston and B. henselae Marseille by Two-dimensional Gel Electrophoresis

To compare the protein difference between B. henselae Houston and B. henselae Marseille by two-dimensional gel electrophoresis. Method Protein samples were prepared by vorterx, ultrasonic treatment, and centrifugation. Protein concentrations were determined by Bradford method. Protein difference was compared by the first IEF and the second SDS-polyacrylamide gel electrophoresis. Results Protein concentrations in samples of Bartonella henselae Houston and Bartonella henselae Marseille were 2.117 μg/μL and 2.200 μg/μL respectively. Sample protein of 40 μg for IPG strips loading was perfect. The results of 2-DE in pH 4 to 7 IPG strips showed that the total protein spots of Bartonella henselae Houston and Bartonella henselae Marseille were 375 and 379 respectively, 95% of the spots were the same between the two strains of Bartonella henselae. Conclusion The procedure of 2-DE may prove successful for the proteomic analysis of Bartonella henselae. Bartonella henselae Houston and Bartonella henselae Marseille are different genotypes.

Two-dimensional gel electrophoresis and surface-enhanced laser desorption ionization-time of flight-mass spectrometry for detection of protein expression profiles in the hippocampus following closed brain injury

Gene expression profile changes in brain regions following traumatic brain injury at the gene level cannot sufficiently elucidate gene expression time, expression amount, protein post-translational processing or modification. Therefore, it is necessary to quantitatively analyze the gene expression profile using proteomic techniques. In the present study, we established a rat model of closed brain injury using Marmarou＇s weight-drop device, and investigated hippocampal differential protein expression using two-dimensional gel electrophoresis and surface-enhanced laser desorption ionization-time of flight-mass spectrometry. A total of 364 protein peaks were detected on weak cation exchange-2 protein chips, including 37 differential protein peaks. 345 protein peaks were detected on immobilized metal affinity capture arrays-Cu, including 12 differential protein peaks Further examination of these differential proteins revealed that glucose-regulated protein and proteasome subunit alpha type 3 expression were significantly upregulated post-injury. These results indicate that brain injury can alter protein expression in the hippocampus, and that glucose-regulated protein and proteasome subunit alpha type 3 are closely associated with the occurrence and development of traumatic brain injury.

Establishment of two-dimensional gel electrophoresis for soybean protein isolate and its application

To optimize the conditions for the establishment of two-dimensional gel electrophoresis(2-DE)of soybean protein isolate(SPI),we investigated Ampholine mixture,anodic and cathodic electrolytes,loading amount of sample,acrylamide concentration,p H gradient and gel staining method in twodimensional gel electrophoresis to optimize the protein imaging conditions in two-dimensional gel.The results of mixed-level design experiments showed that Ampholine,loading amount and gel staining method had significant effect(P<0.05)on 2-DE of SPI.The optimal conditions were Ampholine mixture(pH 3–10+pH 5–7 or pH 4–6+pH 5–7),loading amount of 2 mg sample and silver staining.Although the acrylamide concentration of the gel,the p H gradient,the anodic and cathodic electrolyte solutions had significant statistical effects on the protein separation degree,the complexity of the protein composition and the visibility of the gel images were more inclined to the 12%gel,the 3–10 pH gradient and the H3PO4/NaOH electrolyte.According to the established conditions,the hydrolyzed products of SPI emulsion were determined by 2-DE,and the dynamic changes of protein in the process of enzymatic hydrolysis were described.

Improvement of Two-Dimensional Gel Electrophoresis for Study of Corm Formation Related Proteins in vitro from Taro (Colocasia esculenta)

Efficient and reproducible sample preparation prior to 2D-PAGE (two-dimensional polyacrylamide gel electrophoresis) is a critical step in achieving accurate and reliable data. In this paper, we described a method to prepare protein samples of taro that was compatible with subsequent analysis using 2D-PAGE. We compared proteins from shoot basal region from 0 d and 2 d after the beginning of tuberization. By this method we got about (2 000) spots and high reproducibility. Additionally some changes of protein expression were found.

Specific protein expression in a rat model of early focal cerebral ischemia:Fluorescent two-dimensional difference gel electrophoresis

BACKGROUND： The use of fluorescent two-dimensional difference gel electrophoresis （2D-DIGE） has been shown to compensate for the shortcomings of conventional two-dimensional gel electrophoresis, such as poor repeatability and large systematic errors. However, little information is presently available regarding the use of 2D-DIGE to investigate mechanisms of ischemic cerebrovascular diseases. Plasma and body fluids have been utilized in proteomic technology to study ischemic cerebrovascular diseases. OBJECTIVE： To perform proteomic analysis of fresh rat brain tissue in peripheral ischemic regions using 2D-DIGE 6 hours after middle cerebral artery occlusion （MCAO）, and to identify specific proteins closely associated with early ischemic cerebrovascular diseases. DESIGN, TIME AND SETTING： Proteomics-based, randomized, controlled, animal experiment was performed at the Laboratories of Neurology and Proteomics, Jilin University between January and April 2006. MATERIALS： 2, 3, 5-triphenyl tetrazolium chloride was purchased from Sigma, USA. Ettan DALTSix system, DeCyder DIA V5.0 differential analysis software, and Ettan matrix-assisted laser desorption/ionization time-of-flight mass spectrometer （MALDI-TOF-MS） were purchased from Amersham Bioscience, Sweden. METHODS： Eight healthy, male, Wistar rats were randomized to experimental and control groups, with four rats in each group. In the experimental group, rat models of focal cerebral ischemia were established by MCAO. In the control group, the internal and external carotid arteries were exposed and then immediately sutured, and the remaining procedures were identical to the experimental group. MAIN OUTCOME MEASURES： At 6 hours after cerebral ischemia, protein expression in the peripheral ischemia region of the experimental group was compared with the control group using 2D-DIGE. Protein spots that exhibited statistical differences between experimental and control groups with 〉 1.4 attributable risk were screened using DeCyder DIA V5.0 differential analysis software. Differential proteins were identified using MALDI-TOF-MS. RESULTS： Triphenyl tetrazolium chloride staining results revealed pink, normal brain tissue and white, ischemic brain tissue, suggesting successful MCAO establishment. The average matching rate of four 2D-DIGE gels was 92.4%. There were （1 758 ± 43） protein spots on each gel, with similar distribution modes. At 6 hours after focal cerebral ischemia, 13 protein spots exhibited marked expression changes, including significantly increased （n = 7） and decreased （n = 6） expression （P 〈 0.05）. MALDI-TOF-MS results revealed two differential protein spots： a-tubulin and heat shock protein 27, which were significantly decreased in the experimental group compared with the control group （P 〈 0.05）. CONCLUSION： Thirteen protein spots with expression changes were revealed by 2D-DIGE proteomics technology. Of them, a-tubulin and heat shock protein 27 expressions were markedly decreased during the early stage of cerebral ischemia. These two proteins were presumed to be proteins associated with early ischemic cerebrovascular diseases.

Differential analysis of two-dimensional gel electrophoresis profiles of spermatozoa protein in human normal motility sperm and idiopathic asthenospermia

Objective: To evaluate the application of two-dimensional electrophoresis in the research of differentially expressed proteins in the human asthenospermia. Methods: Two-dimensional gel electrophoresis was performed on 4 normal sperm samples from healthy men and 4 sperm samples from 4 asthenospermia patients. After silver staining, the differential expression proteins were analyzed by PDQuest 2D analysis software. Results: Six differential protein spots were identified. Four spots showed increased expression in the control gels compared with the patient gels. Conclusion: The protein profiles of differential expression between the normal spermatozoa and idiopathic asthenospermia were established and some differential proteins were found. The data of this study would establish the better fundament for further isolation and identification of differentially expressed proteins in human asthenospermia sperm.

Protein expression of sensory and motor nerves Two-dimensional gel electrophoresis and mass spectrometry

The present study utilized samples from bilateral motor branches of the femoral nerve, as well as saphenous nerves, ventral roots, and dorsal roots of the spinal cord, to detect differential protein expression using two-dimensional gel electrophoresis and nano ultra-high performance liquid chromatography electrospray ionization mass spectrometry tandem mass spectrometry techniques. A mass spectrum was identified using the Mascot search. Results revealed differential expression of 11 proteins, including transgelin, Ig kappa chain precursor, plasma glutathione peroxidase precursor, an unnamed protein product （gil55628）, gfyceraldehyde-3-phosphate dehydrogenase-like protein, lactoylgfutathione lyase, adenyfate kinase isozyme 1, two unnamed proteins products （gil55628 and gi11334163）, and poly（rC）-binding protein 1 in motor and sensory nerves. Results suggested that these proteins played roles in specific nerve regeneration following peripheral nerve injury and served as specific markers for motor and sensory nerves.

Proteome analysis of round-headed and normal spermatozoa by 2-D fluorescence difference gel electrophoresis and mass spectrometry

Globozoospermia is a severe form of teratozoospermia characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. Globozoospermia is diagnosed by the presence of 100% round-headed spermatozoa on semen analysis, and patients with this condition are absolutely infertile. The objective of this study was to investigate the differences in protein expression between human round- headed and normal spermatozoa. Two-dimensional （2-D） fluorescence difference gel electrophoresis （DIGE） coupled with mass spectrometry （MS） was used in this study. Over 61 protein spots were analysed in each paired normal/round-headed comparison, using DIGE technology along with an internal standard. In total, 35 protein spots identified by tandem mass spectrometry （MS/MS） exhibited significant changes （paired t-test, P 〈 0.05） in the expression level between normal and round-headed spermatozoa. A total of nine proteins were found to be upregulated and 26 proteins were found to be downregulated in round-headed spermatozoa compared with normal spermatozoa. The differentially expressed proteins that we identified may have important roles in a variety of cellular processes and structures, including spermatogenesis, cell skeleton, metabolism and spermatozoa motility.

Two-dimensional Electrophoresis Analysis of Differential Protein Expression in Squamous Carcinoma of the Cervix

Objective： To establish and optimize the two-dimensional gel electrophoresis （2-DE） maps of squamous carcinoma of the cervix and to study the protein difference between squamous carcinoma of the cervix （SCC） and normal cervical tissue. Methods： Using Two-dimensional gel electrophoresis followed by computer-assisted image analysis, the differential proteins between squamous carcinoma of the cervical tissue and normal cervical tissue were compared. Then using matrix-assisted laser desorption/ionization-time of flight mass spectrometry, the differential proteins were identified. Results： The well-resolved and reproducible two-dimensional gel electrophoresis patterns of squamous carcinoma of the cervix tissue and normal cervical tissue were obtained. After silver staining, the average matching ratio of squamous carcinoma of the cervix was 86.1%. There was a good reproducibility of spot position in 2-DE map, with average deviation in IEF direction of 0.95±0.13 mm, while in SDS-PAGE direction it was 1.20±0.18 mm. Ten protein spots were identified by mass spectrometry, some of which were involved in cell proliferation, cell apoptosis, intracellular enzymes, structural proteins, cycle regulation, and tumor occurrence. Conclusion： The differentially expressed proteins provide a fundamental basis for further study of human squamous carcinoma of the cervix and screening of its specific markers.

Cerebrospinal fluid diagnostic markers for two-dimensional electrophoresis-mass spectrometry in Parkinson’s disease patients

BACKGROUND： Previous studies have confirmed the existence of specific proteins in body fluid of Parkinson＇s disease （PD） patients. However, the existing research has contained several interference factors with poor reproducibility and has not focused on patients grouped according to disease duration. OBJECTIVE： To verify differential expression of proteins in cerebrospinal fluid of PD patients grouped in order of disease severity through the use of two-dimensional electrophoresis-mass spectrometry methods. DESIGN, TIME AND SETTING： The proteomic-based, case-control study was performed between September 2008 and June 2009 at the Key Laboratory of Neurology in the First Affiliated Hospital of Chongqing Medical University. PARTICIPANTS： A total of 52 outpatients and/or inpatients, who were admitted to the Department of Neurology in the First Affiliated Hospital of Chongqing Medical University between 2008 and 2009, were randomized into the present study. Among them, 27 PD patients served as the PD group and were assigned to three subgroups according to modified Webster, Hoehn, and Yahr rating scales： 14 = mild, 8 = moderate, and 5 = severe; non-PD group of 16 patients included 5 cases of viral meningitis, 3 cases of acute myelitis, 1 case of Guillain-Barre syndrome, 2 cases of tuberculous meningitis, 2 cases of restless legs syndrome, and 3 cases of essential tremor; control group （n = 9） consisted of muscular tension headache in 6 cases, as well as syncope, trigeminal neuralgia, idiopathic orthostatic hypotension in 1 case. METHODS： Cerebrospinal fluid was collected from the involved patients using the lumbar puncture method. Proteins in the cerebrospinal fluid were separated by two-dimensional electrophoresis. MAIN OUTCOME MEASURES： Characteristics of protein electrophoresis patterns were analyzed, differentially expressed proteins were detected using matrix-assisted laser desorption ionization time of flight mass spectrometry, and protein data were analyzed in the Mascot database. RESULTS： Five protein electropherograms were analyzed by PDQuest 8.0, and （789 ± 32） protein spots were observed. There were significant differences in four protein spots in each of the PD sub-groups compared with the non-disease and control groups. Expression was down-regulated in three protein spots and up-regulated in one protein spot; 100% repetition rate was observed in four protein spots. According to the Mascot database, protein spots with down-regulated expression were as follows： DNA-guided RNA polymerase III subunit RPC5 （score： 50 points）; double serine, threonine, and tyrosine protein kinase （score： 64 points, P 〈 0.05）; activity-regulated cytoskeleton-associated protein （score： 58 points, P 〈 0.05）. However, G2 mitotic-specific cyclin was up-regulated （score： 84 points, P 〈 0.05）. CONCLUSION： Differential protein expression in the cerebrospinal fluid of PD patients was detected by two-dimensional electrophoresis-mass spectrometry, revealing changes in DNA-guided RNA polymerase III subunit RPC5, double serine, threonine, and tyrosine protein kinase, activity-regulated cytoskeleton-associated protein, and G2 mitotic cell cyclin, with good reproducibility.

Two-dimensional gel electrophoresis analysis of the proteomes expressed in the human hepatoma cell line BEL-7404 and normal liver cell line L-02

Proteome analysis technology has been used extensively in conducting discovery research of biology and has become one of the most essential technologies in functional genomics. The proteomes of the human hepatoma cell line BEL-7404 and the normal human liver cell line L-02 have been separated by high resolution two-dimensional gel electrophoresis (2-DE) with immobilized pH gradient isoelectric focusing (IPG-IEF) in the first dimension and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) in the second dimension (IPG-DALT). The resulting images have been analyzed using 2-D analysis software. Quantitative analysis reveals that 7 protein spots are detected only in hepatoma BEL-7404 cells, 14 only in L-02 cells, and 78 protein spots show significant fluctuation in quantity in both cell lines (P【0.01). These protein spots have been displayed on a proteome differential expression map. Analysis for the reproducibility of 2-DE indicates that the positional variability in the IEF dimension

Two-dimensional electrophoretogram of acute brain injury-associated proteins Comparison between injured and normal cerebral cortex

BACKGROUND： To this date, specific molecular markers for early diagnosis and prognosis monitoring of craniocerebral injury in clinical medicine do not exist. Therefore, differential detection of specific proteins might play an important role in diagnosis and treatment of this type of brain injury. OBJECTIVE： To compare differential cerebral cortical protein expression of craniocerebral injury patients and normal subjects through the use of proteomics. DESIGN： Contrast observation. SETTING： Department of Neurosurgery, Xiangya Hospital of Central South University. PARTICIPANTS： Ten patients （6 males and 4 females, 20 58 years old）, with severe craniocerebral injury, were selected at the Department of Neurosurgery, Xiangya Hospital of Central South University, from June 2004 to December 2006. All patients were diagnosed with CT test and Glasgow test （scores 〈 8）. Surgery was performed 4-12 hours after craniocerebral injury, and injured cortical tissues of the frontal and temporal lobes were resected for sampling. At the same time, control cortical tissues were collected from frontal and temporal lobes of 2 epileptic patients who underwent hippocampus-nucleus amygdala resection, and 2 lateral ventricular tumor patients who underwent tumor resection. The participants and their relatives provided confirmed consent, and this study received confirrned consent from the local ethics committee. METHODS： Ten samples from injured patients and 4 normal samples were compared through the use of proteomics. Total protein was separated by using two-dimensional electrophoresis with immobilized pH gradients, and the differential protein expressions were compared using image analysis after blue-sliver staining. Differential protein spot expressions were analyzed with a matrix-assisted laser desorption/ionization time of flight mass spectrometry （MALDI/TOF MS） and electrospray ionization-quadrupole time of flight mass spectrometry （ESI-Qq TOF MS）. MAIN OUTCOME MEASURES：① Two-dimensional electrophoresis of protein from cerebral cortex; ② differential protein expression. RESULTS： ① Two-dimensional electrophoresis of protein from cerebral cortex： two-dimensional gel electrophoretogram, which is considered to have high resolution and consistent duplication, was performed on injured cortical tissues and normal cortical tissues. The image analysis system detected 21 differential protein spots. ② Differential protein spot expressions： mass spectrometry resulted in 17 differential protein spots that related to metabolic response, oxidative stress response, and signal transduction. CONCLUSION： MALDI/TOF MS and ESI-Qq TOF MS are exceptional methods for evaluating differential protein expression. Results from this study indicated 17 different craniocerebral injury-associated proteins.

Analysis of Proteomic Components of Sera from Patients with Uremia by Two Dimensional Electrophoresis and Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry

Summary： The different sera proteomic components between uremia patients and normal subjects were studied through two-dimensional gel electrophoresis technique. Immobilized pH gradient two- dimensional polyacrylamide gel electrophoresis （2DE）, silver staining, ImageMaster 2D 5.0 analysis software, matrix assisted laser desorption ionization-time of flight mass spectrometry （MALDI-TOF-TOF-MS） and IPI human database searching were used to separate and identify the proteome of the sera from the patients with uremia. The results showed that satisfactory 2DE patterns of the serum proteins were obtained. Twenty-six protein spots showed significant difference in quantity in uremia patients, and 20 protein spots were identified by MALDI-TOF-TOF-MS. It was concluded that good reproducibility could be obtained by applying immobilized pH gradient 2DE to separate and identify the proteome in serum, which provided the foundation for the further study on uremia toxins oertaining to orotein.

Two-dimensional gel electrophoresis in bacterial proteomics

Two-dimensional gel electrophoresis(2-DE)is a gel-based technique widely used for analyzing the pro-tein composition of biological samples.It is capable of resolving complex mixtures containing more than a thousand protein components into individual protein spots through the coupling of two orthogonal bio-physical separation techniques:isoelectric focusing(first dimension)and polyacrylamide gel electrophore-sis(second dimension).2-DE is ideally suited for ana-lyzing the entire expressed protein complement of a bacterial cell:its proteome.Its relative simplicity and good reproducibility have led to 2-DE being widely used for exploring proteomics within a wide range of envi-ronmental and medically-relevant bacteria.Here we give a broad overview of the basic principles and his-torical development of gel-based proteomics,and how this powerful approach can be applied for studying bacterial biology and physiology.We highlight specific 2-DE applications that can be used to analyze when,where and how much proteins are expressed.The links between proteomics,genomics and mass spectrometry are discussed.We explore how proteomics involving tandem mass spectrometry can be used to analyze(post-translational)protein modifications or to identify proteins of unknown origin by de novo peptide se-quencing.The use of proteome fractionation tech-niques and non-gel-based proteomic approaches are also discussed.We highlight how the analysis of pro-teins secreted by bacterial cells(secretomes or exo-proteomes)can be used to study infection processes or the immune response.This review is aimed at non-specialists who wish to gain a concise,compre-hensive and contemporary overview of the nature and applications of bacterial proteomics.

PHProteomicDB:A Module for Two-dimensional Gel Electrophoresis Database Creation on Personal Web Sites

PHProteomicDB is a PHP-written module to help researchers in proteomics to share two-dimenslonal gel electrophoresis data using personal web sites. No technical or PHP knowledge is necessary except a few basics about web site management. PHProteomicDB has a user-friendly administration interface to enter and update data. It creates web pages on the fly displaying gel characteristics, gel pictures, and numbered gel spots with their related identifications pointing to their reference pages in protein databanks. The module is freely available at http：//www.huvec.com/index.php3？rub=Download.

2型糖尿病患者肠道拟类菌属和双歧杆菌属多样性的PCR-DGGE指纹图谱分析

目的分析2型糖尿病患者肠道拟类菌属和双歧杆菌属的多样性及其与健康个体的差异,探讨糖尿病与肠道优势菌属的相关性。方法收集2型糖尿病患者和健康志愿者粪样,提取样品中菌群总DNA,利用拟类菌和双歧杆菌16SrRNA种属特异性引物,进行PCR扩增,将产物用变性梯度凝胶电泳分离,获得肠道菌群分子指纹图谱,进行多样性和相似性等特征分析。结果糖尿病组和健康人组样品DGGE图谱多样性指数范围分别是:拟类菌属0.89(0.75～0.95),0.95(0.89～0.97);双歧杆菌属:0.85(0.75～0.94),0.87(0.73～0.93)。组内成对相似性系数累积曲线分析,拟类菌属:小于0.5的Cs值在糖尿病组占到总Cs值个数的85.83%,而健康人组只占到35.71%;双歧杆菌属:小于0.4的Cs值在糖尿病组占到总Cs值个数的90%,健康人组占到总Cs值个数的60.7%。结论糖尿病患者和健康人肠道拟类菌属和双歧杆菌属指纹图呈现个体特异性,糖尿病患者两种菌属多样性与健康个体无显著差异,而糖尿病患者个体之间的相似性较健康个体之间低。

2-DE技术中疏水性和碱性蛋白质的研究进展

双向凝胶电泳(2-DE)具有高分辨率、高通量等特点,已被广泛地用于蛋白质组的分离.但是它在分离疏水性蛋白质和碱性蛋白质时却遇到了极大的挑战.然而,疏水性与碱性蛋白质在全蛋白质中占相当大的比例,且具有很重要的生物学意义.因而,近年来,越来越多的研究者将目标瞄准这些蛋白质,并且取得了一些令人鼓舞的进展:用亚细胞预分离技术,顺序提取法等方法来富集疏水性蛋白质,用一些新的有效的增溶剂如硫脲,ASB-14等来改善疏水性蛋白质的溶解,应用这些技术2-DE可分辨出总平均疏水值达0.80的蛋白质;在碱性蛋白质分离方面,通过等电聚焦预处理,使用窄pH梯度胶条等大大地改善了碱性蛋白质在2-DE中的分离,能分辨出等电点达11.7的蛋白质.现对2-DE技术中疏水性和碱性蛋白质分离的研究进展进行综述.

瑞香狼毒诱导HL-60细胞凋亡和调节SGC-7901细胞bcl-2蛋白表达(英文)

目的 探索瑞香狼素 (SC)抗肿瘤机制。方法 以 HL- 6 0和 SGC- 790 1为靶细胞 ,用 MTT比色法测定细胞增殖抑制 ,荧光显微镜观察凋亡细胞的形态学改变 ,DNA电泳和流式细胞仪检测DNA断裂 ,免疫组化检测 bcl- 2蛋白表达。结果 含 SC药物血清处理细胞 48h后 ,HL- 6 0细胞增殖呈剂量依赖性抑制 ,并表现出典型的凋亡细胞形态学改变及 DNA断裂 :即染色体聚集、核固缩、断裂及阶梯状 DNA电泳条带 ,G1 期前细胞从 11.7%增至 5 7.4% ;而 SGC- 790 1细胞 bcl- 2蛋白表达率从 78.3%下降到 32 .9%。结论 SC可诱导肿瘤细胞凋亡 ,降低 bcl- 2蛋白表达。