Ubiquitin-specific protease 21 promotes tumorigenicity and stemness of colorectal cancer by deubiquitinating and stabilizing ZEB1

BACKGROUND Colorectal cancer(CRC)is one very usual tumor together with higher death rate.Ubiquitin-specific protease 21(USP21)has been confirmed to take part into the regulation of CRC progression through serving as a facilitator.Interestingly,the promotive function of USP21 has also discovered in the progression of CRC.ZEB1 has illustrated to be modulated by USP7,USP22 and USP51 in cancers.However,the regulatory functions of USP21 on ZEB1 in CRC progression need more invest-igations.AIM To investigate the relationship between USP21 and ZEB1 in CRC progression.METHODS The mRNA and protein expressions were assessed through RT-qPCR,western blot and IHC assay.The interaction between USP21 and ZEB1 was evaluated through Co-IP and GST pull down assays.The cell proliferation was detected through colony formation assay.The cell migration and invasion abilities were determined through Transwell assay.The stemness was tested through sphere formation assay.The tumor growth was evaluated through in vivo mice assay.RESULTS In this work,USP21 and ZEB1 exhibited higher expression in CRC,and resulted into poor prognosis.Moreover,the interaction between USP21 and ZEB1 was further investigated.It was demonstrated that USP21 contributed to the stability of ZEB1 through modulating ubiquitination level.In addition,USP21 streng-thened cell proliferation,migration and stemness through regulating ZEB1.At last,through in vivo assays,it was illustrated that USP21/ZEB1 axis aggravated tumor growth.CONCLUSION For the first time,these above findings manifested that USP21 promoted tumorigenicity and stemness of CRC by deubiquitinating and stabilizing ZEB1.This discovery suggested that USP21/ZEB1 axis may provide novel sights for the treatment of CRC.

胃癌组织中IL-32与Apaf-1蛋白的表达及意义

目的 分析胃癌组织中白细胞介素-32(Interleukin-32,IL-32)与凋亡蛋白酶激活因子-1(Apoptotic Protease Activating Factor-1,Apaf-1)的表达及意义。方法 回顾性选取2019年1月—2022年12月南通市肿瘤医院收治的100例胃癌患者的临床资料,分别取其胃癌组织标本(胃癌组)和正常胃黏膜标本(癌旁组),通过免疫组化法(Streptavidin-perosidase,SP)检测胃癌标本与正常标本中IL-32、Apaf-1蛋白的阳性表达情况。结果胃癌组IL-32阳性表达率高于癌旁组,Apaf-1蛋白阳性表达率低于癌旁组,差异有统计学意义(P均<0.05);胃癌患者高中分化程度与低分化程度之间,浸润深度<肌层与≥肌层之间,TNM分期为Ⅰ、Ⅱ期与分期为Ⅲ、Ⅳ期之间以及有无淋巴结转移之间的IL-32、Apaf-1蛋白阳性表达率对比,差异有统计学意义(P均<0.05)。结论 IL-32与Apaf-1蛋白的阳性表达可为胃癌患者的临床诊断和治疗提供重要的参考价值。

子宫动脉血流多普勒超声联合血清PIGF、Vaspin、ESM-1诊断HDP价值

目的:探讨妊娠高血压疾病(HDP)患者子宫动脉血流多普勒超声、血清促血管生成因子(PIGF)、丝氨酸蛋白酶抑制剂(Vaspin)、内皮细胞特异分子-1(ESM-1)水平及其诊断价值。方法:回顾性收集2020年6月-2021年12月本院接诊的HDPL患者86例为病例组,产前检查健康孕妇75例为对照组,检测两组血清PIGF、Vaspin、ESM-1水平及子宫动脉血流参数,分析在诊断HDP价值。结果:病例组血清PIGF(271.56±45.56 pg/ml)低于对照组(330.15±50.35 pg/ml),Vaspin(0.46±0.04 ng/ml)、ESM-1(1.38±0.51μg/L)高于对照组(0.39±0.08 ng/ml、1.01±0.07μg/L),多普勒超声子宫动脉血流阻力指数(RI)(0.79±0.14)、搏动指数(PI)(0.83±0.21)、收缩期峰值流速与舒张末期血流速度比值(S/D)(2.26±0.74)均高于对照组(0.51±0.20、0.44±0.19、1.41±0.35),且病例组妊娠期高血压、轻度子痫前期、重度子痫前期患者上述各指标均有差异(均P<0.05)。受试者工作特征曲线分析,血清PIGF、Vaspin、ESM-1、RI、PI、S/D及各项联合,诊断HDP的曲线下面积分别为0.811、0.780、0.691、0.944、0.860、0.813、0.999,截断值分别为291.56 pg/ml、0.43 ng/ml、1.12μg/L、0.58、0.53、1.87,联合检测的特异度(96.5%)、准确度(93.4%)最高(均P<0.05)。结论:HDP患者血清PIGF、Vaspin、ESM-1、子宫动脉血流参数异常改变,且对HDP有较好诊断价值,本次研究也为靶向药物治疗HDP提供了新思路。

Small ubiquitin-like modifier protein-specific protease 1 and prostate cancer

Small ubiquitin-like modifier protein （SUMO） modification is a highly dynamic process, catalyzed by SUMO- specific activating （El）, conjugating （E2） and ligating （E3） enzymes, and reversed by a family of SUMO-specific proteases （SENPs）. There are six members of the human SENP family, and each SENP has different cellular locations and substrate specificities. However, the precise roles of SENPs in cellular processes have not been elucidated to date. This brief review will focus on recent advances pertaining to the identified targets of SENP 1 and its potential role in prostate cancer.

七种蛋白酶抑制剂对多房棘球蚴DNA损伤诱导样1蛋白活性的影响

目前,多房棘球蚴病(alveolar echinococcosis, AE)尚无有效药物治疗手段,迫切需要开发新型治疗药物。前期研究表明,HIV蛋白酶抑制剂(HIV protease inhibitors, HIV PIs)具有潜在抗寄生虫功能。本文旨在研究HIV PIs对Echinococcus multilocularis(Emu)DNA损伤诱导样1蛋白(DNA damage inducible 1 protein, Ddi1)活性的影响。本研究通过构建真核表达重组载体pFastBac1-Emu Ddi1,在昆虫细胞系Sf9细胞中表达筛选出P1代和P2代,纯化出可溶性Ddi1重组蛋白,然后与目的蛋白的荧光底物检测纯化蛋白的活性,进一步检测沙奎那韦(saquinavir, SQV)、利托那韦(ritonavir, RTV)、安普那韦(amprenavir, APV)、阿扎那韦(atazanavir, ATV)、洛匹那韦(lopinavir, LPV)、福沙那韦(fosamprenavir, Fos)、达芦那韦(darunavir, DRV)等7种HIV PIs对Emu Ddi1重组蛋白活性的抑制能力。结果显示:细胞系内真核表达产物的酶活Km为1.422μmol·L^(-1),具有良好的亲和力和活性,最终筛到沙奎那韦对Ddi1蛋白二聚体活性位点的抑制率达67%,其IC_(50)为34,说明沙奎那韦对Emu Ddi1重组蛋白酶活性具有良好的抑制效果。以上结果提示:沙奎那韦抑制重组蛋白Ddi1的活性,可能成为Ddi1的靶向药物,以期为替代药物或开发联合用药提供基础。

Serine protease HtrA1 expression in human hepatocellular carcinoma

BACKGROUND: HtrA1, a serine protease, is down-regulated in various human solid tumors. Overexpression of HtrA1 in human cancer cells inhibits cell growth and proliferation in vitro and in vivo, suggesting its possible role as a tumor suppressor. METHODS: Immunohistochemistry was used to determine the expression of HtrA1 in 50 hepatocellular carcinoma specimens and adjacent liver tissues. The correlation between the expression of HtrA1 and the clinico-pathologic data were analyzed. RESULTS: The levels of HtrA1 were lower in tumor tissues than in their adjacent liver tissues. Moreover, an inverse relationship was found between HtrA1 expression and the differentiation of hepatocellular carcinoma. Loss of HtrA1 was more frequently found in tumors in Edmondson grade especially in those with venous invasion, compared to tumors in Edmondson grade I-II. Most importantly, patients with higher HtrA1 expression had a better survival rate. CONCLUSION: All these data suggest an important role of HtrA1 in hepatocellular carcinoma development and progression, which may be a new target for its treatment.

长链非编码RNA核富集转录本1对瘢痕成纤维细胞增殖、凋亡和迁移的影响

背景:已有研究阐明核富集转录本1(nuclear enriched abundant transcript 1,NEAT1)下调抑制了瘢痕成纤维细胞的进展,但具体机制尚不完全清楚。目的:探讨长链非编码RNA NEAT1调节miR-136-5p/泛素特异性蛋白酶4(ubiquitin specific protease 4,USP4)轴对瘢痕成纤维细胞生物学行为的影响。方法:将瘢痕成纤维细胞分为5组:si-NC组、空白对照组、si-NEAT1组、si-NEAT1+miR-136-5p inhibitor组、si-NEAT1+inhibitor-NC组,qRT-PCR检测NEAT1、miR-136-5p表达;CCK-8法及EDU染色检测细胞增殖能力;流式细胞术检测细胞凋亡情况;划痕愈合实验检测细胞迁移情况;Western blot检测USP4、p27、Bax、基质金属蛋白酶9、α-平滑肌肌动蛋白、Ⅰ型胶原蛋白α1链蛋白表达;双荧光素酶实验检测NEAT1与miR-136-5p、miR-136-5p与USP4的关系。结果与结论:①与si-NC组比较,si-NEAT1组NEAT1表达、A450值、EDU阳性细胞百分比、划痕愈合率以及USP4、基质金属蛋白酶9、α-平滑肌肌动蛋白、Ⅰ型胶原蛋白α1链蛋白表达降低(P<0.05),miR-136-5p表达、细胞凋亡率及p27、Bax蛋白表达升高(P<0.05);②miR-136-5p inhibitor逆转了沉默NEAT1对瘢痕成纤维细胞生物学行为的影响;③miR-136-5p与NEAT1、miR-136-5p与USP4存在靶向调控关系。结果表明,沉默NEAT1可能通过调控miR-136-5p/USP4轴抑制瘢痕成纤维细胞的增殖和迁移,诱导其凋亡。

动态增强MRI联合血清SPINK1水平诊断原发性肝癌价值研究

目的探讨动态增强磁共振(MRI)联合血清丝氨酸蛋白酶抑制剂因子Kazal 1型(SPTINK1)水平诊断原发性肝癌(PLC)的价值。方法2020年4月~2023年4月我院收治的乙型肝炎肝硬化患者204例,均接受动态增强MRI扫描检查,对肝内占位性病变者行细针穿刺病理学检查。采用ELISA法检测血清SPTINK1和甲胎蛋白水平。应用二元多因素Logistic回归分析诊断HCC的血清指标,应用受试者工作特征曲线(ROC)分析血清指标的诊断效能。结果在204例乙型肝炎肝硬化患者中,发现肝内占位性病变并经穿刺病理学检查诊断肝细胞癌(HCC)30例(14.7%);HCC组血清SPTINK1和AFP水平分别为(23.9±5.2)ng/mL和(426.5±67.0)ng/mL,显著高于肝硬化组【分别为(7.4±2.1)ng/mL和(14.4±4.3)ng/mL,P<0.05】;血清SPTINK1(OR:3.69,95%CI:1.08~12.49)和甲胎蛋白(AFP,OR:3.54,95%CI:1.04~11.98)均与HCC高度相关;以血清AFP水平大于等于360.1 ng/mL为截断点,其诊断HCC的AUC为0.80(95%CI:0.72~0.89),灵敏度和特异度分别为71%和73%,以血清SPTINK1水平等于或大于15.6 ng/mL为截断点,其诊断HCC的AUC为0.82(95%CI:0.74~0.91),灵敏度和特异度分别为82%和79%。结论在肝硬化患者,经影像学检查发现肝内占位性病变时,血清SPINK1和AFP水平升高可以帮助初步判断病变性质,应尽早进行穿刺病理学检查。

2型糖尿病患者血清E盒锌指蛋白1和泛素化特异性蛋白酶22表达水平与糖脂代谢及胰岛素抵抗的关系

目的检测2型糖尿病患者血清E盒锌指蛋白1(ZEB1)和泛素化特异性蛋白酶22(USP22)基因的表达水平,分析两者与糖脂代谢及胰岛素抵抗的关系。方法选择2020年6月至2023年6月苏州大学附属第一医院诊治的120例2型糖尿病患者为研究对象(糖尿病组),同时选择同期在该院进行体检的120例健康者作为对照组。采用qRT-PCR法检测血清ZEB1 mRNA和USP22 mRNA表达水平;Pearson法分析2型糖尿病患者血清ZEB1 mRNA和USP22 mRNA表达水平的相关性,及两者与体重指数(BMI)、三酰甘油(TG)、总胆固醇(TC)、空腹血糖(FPG)、空腹胰岛素(FIns)、胰岛素抵抗指数(HOMA-IR)、胰岛素敏感性指数(ISI)、胰岛β细胞功能指数(HOMA-β)相关性;多元线性回归分析2型糖尿病患者血清ZEB1 mRNA和USP22 mRNA表达水平的影响因素。结果糖尿病组患者的BMI、TG、TC、FPG、FIns、HOMA-IR、ZEB1 mRNA、USP22 mRNA水平明显高于对照组,ISI、HOMA-β明显低于对照组,差异有统计学意义(P<0.05)。经Pearson相关分析显示,2型糖尿病患者血清ZEB1 mRNA和USP22 mRNA表达水平正相关(r=0.425,P<0.001);血清ZEB1 mRNA和USP22 mRNA表达水平均与FPG、FIns、HOMA-IR呈正相关(P<0.05),均与ISI、HOMA-β呈负相关(P<0.05)。多元线性回归分析显示,FIns升高、ISI降低是血清ZEB1 mRNA表达水平的影响因素(P<0.05);FPG升高是USP22 mRNA表达水平的影响因素(P<0.05)。结论2型糖尿病患者血清中ZEB1 mRAN和USP22 mRAN表达具有正相关关系,且两者与部分糖脂代谢和胰岛素抵抗指标具有相关性。

Effects of fluoxetine on mast cell morphology and protease-1 expression in gastric antrum in a rat model of depression

AIM: To investigate the effects of fluoxetine on depression-induced changes of mast cell morphology and protease-1 (rMCP-1) expression in rats. METHODS: A Sprague-Dawley rat model of chronic stress-induced depression was established. Fifty experimental rats were randomly divided into the following groups: normal control group, fluoxetine + normal control group, depressed model group, saline + depressed model group, and fluoxetine + depressed model group. Laser scanning confocal microscopy (LSCM) immunofluorecence and RT-PCR techniques were used to investigate rMCP-1 expression in gastric antrum. Mast cell morphology was observed under transmission electron microscopy. ANOVA was used for statistical analysis among groups.RESULTS: Morphologic observation indicated that depression induced mast cell proliferation, activation, and granule hyperplasia. Compared with the normal control group, the average immunofluorescence intensity of gastric antrum rMCP-1 significantly increased in depressed model group (37.4 ± 7.7 vs 24.5 ± 5.6, P < 0.01) or saline + depressed model group (39.9 ± 5.0 vs 24.5 ± 5.6, P < 0.01), while there was no significant difference between fluoxetine + normal control group (23.1 ± 3.4) or fluoxetine + depressed model group (26.1 ± 3.6) and normal control group.The average level of rMCP-1mRNA of gastric antrum significantly increased in depressed model group (0.759 ± 0.357 vs 0.476 ± 0.029, P < 0.01) or saline + depressed model group (0.781 ± 0.451 vs 0.476 ± 0.029, P < 0.01 ), while no significant difference was found between fluoxetine + normal control group (0.460 ± 0.027) or fluoxetine + depressed model group (0.488 ± 0.030) and normal control group. Fluoxetine showed partial inhibitive effects on mast cell ultrastructural alterations and de-regulated rMCP-1 expression in gastric antrum of the depressed rat model.CONCLUSION: Chronic stress can induce mast cell proliferation, activation, and granule hyperplasia in gastric antrum. Fluoxetine counteracts such changes in the depressed rat model.

DNA Methylation Profiles of Protease Nexin 1 (SERPINE2) Gene in Human Cell Lines

Objective： To investigated whether epigenetic mechanisms contribute to the variable expression of variable protease nexin1（PN-1） encoded by the SERPINE2 gene in different cell types. Methods： Working with 5 human cell lines, we determined the CpG methylation status within two CpG islands in the SERPINE2 gene by bisulphate sequencing and the PN-1 mRNA level by Q-RT PCR. Results： A CpG island spanning the transcription initiation site showed little methylation in 3 of the cell lines and substantial methylation in 2 of the cell lines. A CpG island covering the translation starting site showed full methylation in all investigated cell lines. Methylation within the CpG island was not randomly distributed, but showed accumulation at specific sites. However, we were not able to distinguish any patterns which related the methylation frequency to the gene expression level. Inhibition of CpG methylation with 5-aza-2’-deoxycytidine led to a several fold increase in PN-1 mRNA levels, but based on the results on CpG methylation in the CpG island spanning the transcript, the effect is most likely indirect. Conclusion： We have carefully mapped the CpG methylation pattern in two CpG islands in the 5’ part of the SERPINE2 gene without finding any obvious inverse correlation between methylation frequency and expression level.

Hippocampal expression of apoptotic protease activating factor-1 following diffuse axonal injury under mild hypothermia

The influence of mild hypothermia on neural cell apoptosis remains poorly understood. Therefore, the present study established rat models of diffuse axonal injury （DAI） at 33℃. Morris water maze results demonstrated significantly better learning and memory functions in DAI rats with hypothermia compared with DAI rats with normothermia. Expression of apoptotic protease activating factor-1 in the hippocampal CA1 region was significantly lower in the DAI hypothermia group compared with the DAI normothermia group. Expression of apoptotic protease activating factor-1 positively correlated with latency, but negatively correlated with platform location times and time of swimming in the quadrant area. Results suggested that post-traumatic mild hypothermia in a rat model of DAI could provide cerebral protection by attenuating expression of apoptotic protease activating factor-1.

冠心病心绞痛患者血清内脏脂肪特异性丝氨酸蛋白酶抑制剂、不规则趋化因子、单核细胞趋化蛋白-1与心功能、心肌损伤指标相关性分析

目的:探讨冠心病(CHD)心绞痛患者血清内脏脂肪特异性丝氨酸蛋白酶抑制剂(Vaspin)、单核细胞趋化蛋白-1(MCP-1)、不规则趋化因子(Fractalkine)与心功能、心肌损伤指标的相关性。方法:选取150例CHD心绞痛患者作为观察组(不稳定型心绞痛患者64例为A组、稳定型心绞痛患者86例为B组),同期收治的164例非CHD患者为C组。比较三组血清Fractalkine、Vaspin、MCP-1水平、心功能指标及心肌损伤指标,相关性采用Pearson相关性分析。结果:A组血清Vaspin水平低于B组、C组,且与C组比较,B组更低;A组血清Fractalkine、MCP-1水平高于B组、C组,且与C组比较,B组更高(均P<0.05)。A组左心室射血分数(LVEF)、左心室短轴缩短率(FS)低于B组、C组,且与C组比较,B组更低;A组左心室舒张末期内径(LVEDD)、左室收缩末期内径(LVESD)高于B组、C组,且与C组比较,B组更高(均P<0.05)。A组各心肌损伤指标水平均高于B组、C组,且与C组比较,B组更高(均P<0.05)。Pearson相关性分析:CHD心绞痛患者血清Vaspins水平与LVEF、FS成正比;血清Vaspins水平与LVEDD、LVESD、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、肌钙蛋白I(cTnI)、心型脂肪酸结合蛋白(H-FABP)成反比;血清Fractalkine、MCP-1与LVEF、FS成反比;血清Fractalkine、MCP-1与LVEDD、LVESD、CK、CK-MB、cTnI、H-FABP成正比(均P<0.05)。结论:随着CHD心绞痛患者病情加重,患者心功能及心肌损伤越严重,且患者血清Vaspins、Fractalkine、MCP-1与患者心功能及心肌损伤具有密切联系,临床可根据其水平变化评估病情进展情况。

芪地糖肾方调控NLRP3/Caspase-1/GSDMD通路介导高糖刺激肾小球内皮细胞焦亡的研究

目的 探究芪地糖肾方通过NOD样受体家族热蛋白结构域相关蛋白3/半胱氨酸天冬氨酸蛋白酶-1/消皮素D蛋白(NLRP3/Caspase-1/GSDMD)通路介导高糖刺激的肾小球内皮细胞焦亡的作用。方法 将肾小球内皮细胞分为正常组、高糖组、芪地糖肾方组,分别予完全培养基、30 mmol/L高糖培养基、30 mmol/L高糖培养基+芪地糖肾方100μg/mL培养48 h,采用细胞免疫荧光染色法观察细胞中NLRP3表达情况及细胞骨架情况,采用Western blot法检测细胞中NOD样受体热蛋白结构域相关蛋白3(NLRP3)、半胱氨酸天冬氨酸蛋白酶1(Caspase-1)、消皮素D蛋白(GSDMD)、凋亡相关斑点样蛋白(ASC)、白细胞介素-1β(IL-1β)、白细胞介素-18(IL-18)表达情况。结果 与正常组比较,高糖组细胞中NLRP3、Caspase-1、GSDMD、ASC、IL-18、IL-1β蛋白相对表达量均明显升高(P均<0.05),NLRP3荧光表达信号增强,细胞骨架损伤明显;与高糖组比较,芪地糖肾方组NLRP3、Caspase-1、GSDMD、ASC、IL-18、IL-1β蛋白相对表达量均明显降低(P均<0.05),NLRP3荧光表达信号减弱,细胞骨架损伤状态改善。结论 芪地糖肾方可通过抑制NLRP3/Caspase-1/GSDMD焦亡相关通路激活改善高糖诱导的肾小球内皮细胞损伤。

Synthesis of N1-Substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyra-zolethiocarboxamide as Novel Small Molecule Inhibitors of Cysteine Protease of T.cruzi

A series of N1-substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyrazolethiocarboxamide were prepared from the Mannich bases of aryl ketones in good yields. Some derivatives were found to be active against the cysteine protease of T.cruzi..

A new approach for HIV-1 protease cleavage site prediction combined with feature selection

Acquired immunodeficiency syndrome (AIDS) is a fatal disease which highly threatens the health of human being. Human immunodeficiency virus (HIV) is the pathogeny for this disease. Investigating HIV-1 protease cleavage sites can help researchers find or develop protease inhibitors which can restrain the replication of HIV-1, thus resisting AIDS. Feature selection is a new approach for solving the HIV-1 protease cleavage site prediction task and it’s a key point in our research. Comparing with the previous work, there are several advantages in our work. First, a filter method is used to eliminate the redundant features. Second, besides traditional orthogonal encoding (OE), two kinds of newly proposed features extracted by conducting principal component analysis (PCA) and non-linear Fisher transformation (NLF) on AAindex database are used. The two new features are proven to perform better than OE. Third, the data set used here is largely expanded to 1922 samples. Also to improve prediction performance, we conduct parameter optimization for SVM, thus the classifier can obtain better prediction capability. We also fuse the three kinds of features to make sure comprehensive feature representation and improve prediction performance. To effectively evaluate the prediction performance of our method, five parameters, which are much more than previous work, are used to conduct complete comparison. The experimental results of our method show that our method gain better performance than the state of art method. This means that the feature selection combined with feature fusion and classifier parameter optimization can effectively improve HIV-1 cleavage site prediction. Moreover, our work can provide useful help for HIV-1 protease inhibitor developing in the future.

酶解法制备核桃谷蛋白-1 ACE抑制肽的工艺优化

为获得优质的核桃蛋白血管紧张素转化酶(ACE)抑制肽的制备原料及优化其制备工艺,采用连续提取法从脱脂核桃粕中依次分离出清蛋白、球蛋白、醇溶蛋白、谷蛋白-1和谷蛋白-25种组分蛋白,测定5种组分蛋白的占比及ACE抑制率,以ACE抑制率最大的组分蛋白作为原料采用酶解法制备ACE抑制肽,在筛选出最适酶解用酶基础上,采用单因素试验与响应面试验优化酶解制备核桃蛋白ACE抑制肽的工艺。结果表明:5种组分蛋白中谷蛋白-1占比仅次于谷蛋白-2,且其ACE抑制率最高,以核桃谷蛋白-1为原料,在筛选出胃蛋白酶作为酶解用酶基础上,经工艺优化得到最优的酶解法制备核桃谷蛋白-1 ACE抑制肽的工艺条件为酶解温度46℃、酶解时间6 h、酶用量4.2%(以底物质量计)、酶解pH 1.6,在该条件下所得核桃谷蛋白-1酶解液的ACE抑制率为(50.08±2.34)%。因此,核桃谷蛋白-1经胃蛋白酶酶解可生产ACE抑制活性较高的核桃多肽。

Exploring QSARs for Inhibitory Activity of Cyclic Urea and Nonpeptide-Cyclic Cyanoguanidine Derivatives HIV-1 Protease Inhibitors by Artificial Neural Network

Quantitative structure–activity relationship study using artificial neural network (ANN) methodology were conducted to predict the inhibition constants of 127 symmetrical and unsymmetrical cyclic urea and cyclic cyanoguanidine derivatives containing different substituent groups such as: benzyl, isopropyl, 4-hydroxybenzyl, ketone, oxime, pyrazole, imidazole, triazole and having anti-HIV-1 protease activities. The results obtained by artificial neural network give advanced regression models with good prediction ability. The two optimal artificial neural network models obtained have coefficients of determination of 0.746 and 0.756. The lowest prediction’s root mean square error obtained is 0.607. Artificial neural networks provide improved models for heterogeneous data sets without splitting them into families. Both the external and cross-validation methods are used to validate the performances of the resulting models. Randomization test is employed to check the suitability of the models.

Monitoring the autoproteolysis of hiv-1 protease by site-directed spin-labeling and electron paramagnetic resonance spectroscopy

Site-directed spin-labeling with continuous wave electron paramagnetic resonance spectroscopy was used to monitor autoproteolysis of HIV-1 protease, an enzyme essential for viral maturation. Two protein constructs were examined, namely subtype F and the circulating recombinant form CRF01_A/E. As the protease undergoes self-cleavage, protein unfolds and small peptide fragments containing the spin label are generated, which collectively give rise to a sharp spectral component that is easily discernable in the high-field resonance line in the EPR spectrum. By monitoring the intensity of this spectral component over time, the autoproteolytic stability of each construct was characterized under various conditions. Data were collected for samples stored at 4 °C, 25 °C, and 37 °C, and on a subtype F HIV-1 protease sample stored at 25 °C and containing the FDA-approved protease inhibitor Tipranavir. As expected, the rate of autoproteolysis decreased as the storage temperature was lowered. Minimal autoproteolysis was seen for the sample that contained Tipranavir, providing direction for future spectroscopic studies of active protease samples. When compared to standard methods of monitoring protein degradation such as gel electrophoresis or chromatographic analyses, spin-labeling with CW EPR offers a facile, real-time, non-consuming way to monitor autoproteolysis or protein degradation. Additionally, mass spectrometry studies revealed that the N-termini of both constructs are sensitive to degradation and that the sites of specific autoproteolysis vary.

miR-23a和APAF-1在子宫内膜癌中的表达及意义

目的观察子宫内膜癌组织中微小RNA-23a(miR-23a)与凋亡蛋白酶活化因子-1(APAF-1)的表达变化并分析其临床意义。方法选取2018年5月至2020年5月于我院进行子宫内膜癌切除手术的123例标本为子宫内膜癌组,另选取其癌旁组织为正常组。检测子宫内膜组织中miR-23a与APAF-1的表达情况;分析miR-23a和APAF-1与患者临床病理的关系及二者的相关性,Kaplan-Meier法分析两指标对患者的生存情况的影响。结果与正常组相比,子宫内膜癌组miR-23a的表达升高,APAF-1 mRNA及蛋白表达降低(P<0.05);miR-23a、APAF-1均与临床分期、组织分化程度及肌层浸润显著相关(P<0.05);miR-23a与APAF-1呈显著负相关(P<0.05);Kaplan-Meier曲线显示miR-23a低表达组与APAF-1阳性表达组中的PFS、OS显著高于miR-23a高表达组和APAF-1阴性表达组(P<0.05)。结论子宫内膜癌中miR-23a表达升高,APAF-1降低,二者与子宫内膜癌的发展及患者预后相关,有望成为临床上评估早期患者疾病进展及预后的生物标记物。