血管紧张素转化酶活性抑制剂──丝素肽的分离、纯化和结构鉴定

可溶性丝素粉末经碱性蛋白酶Alcalase水解后 ,其酶解产物对血管紧张素转化酶 (ACE)的活性有很强的抑制作用。采用凝胶过滤色谱SephadexG 15和反相高效液相色谱 (RP HPLC)对水解度为 2 0 %的酶解产物进行分离纯化 ,利用质谱鉴定其中一种ACE抑制剂是肽 ,其结构为Gly Tyr。

酶快速反应法测纤溶酶抑制剂活性的方法学探讨

目的 建立测定PI活性的酶快速反应法 ,并探讨其在脑梗死、重症肝病等疾病中的临床意义。方法 用酶快速反应法对 2 6例健康对照者和 83例病人血浆中的PI活性进行分析。结果 酶快速反应法特异性好 ,重复性好 ,灵敏度高 ,线性范围宽。结论 酶快速反应法测定PI活性具有可靠性 ,更能正确的反映血中PI水平 。

乙型肝炎病毒活性位点聚合酶抑制剂核苷酸——ATI-2173

ATI-2173是Antios Therapeutics公司研发的第二代活性位点聚合酶抑制剂核苷酸(ASPINs),是第一代ASPINs克拉夫定经5’-磷酰胺修饰的前药,旨在改善克拉夫定的药动学特征,降低克拉夫定全身暴露水平以及引起骨骼肌病的风险,目前该药物正在进行治疗慢性乙型肝炎(CHB)的临床试验。在体外模型研究中,ATI-2173能有效抑制乙型肝炎病毒(HBV)的复制,与拉米夫定和恩替卡韦等链终止核苷类药物具有交叉耐药性,对细胞无毒害性,具有良好的口服利用度和肝脏靶向性。Ⅰ期临床试验结果显示,ATI-2173单独给药时表现出良好的安全性、耐药性及抗病毒活性。Ⅱ期临床试验结果表示,ATI-2173与富马酸替诺福韦酯联合治疗HBC感染患者,具有良好的安全性和抗病毒活性,并且能有效延长治疗后的病毒抑制时间,这对HBV感染患者的长期治疗具有重要意义。本文就ATI-2173的基本信息、作用机制、临床前研究及临床研究等进行概述。

植物防御素的生物学活性及其应用前景

植物防御素是植物界中一类阳离子型多肽,在结构和功能上,它们与早先发现的哺乳动物和昆虫防御素类似。植物防御素的分子量在5kDa左右,其中含有8个保守的半胱氨酸残基。植物防御素的三维结构呈小球形,包括1个α-螺旋和3个反平行的β-折叠片层结构,8个半胱氨酸可以形成3对或4对二硫键,从而构成了Cys稳定的βαββ结构模序。从植物防御素的结构和体外生物学活性,可以看出植物防御素是一类十分复杂的多肽,它的作用不仅仅局限于植物免疫,而应具有广阔的应用前景。

氮离子注入对耐辐射异常球菌SOD活性的影响及其对Mn-SOD的诱导

研究了氮离子注入对耐辐射异常球菌（Ｄｅｉｎｏｃｏｃｃｕｓｒａｄｉｏｄｕｒａｎｓ）细胞内超氧化物歧化酶（ＳＯＤ）活性的影响及其对ＭｎＳＯＤ的诱导。结果表明，当２０ｋｅＶ氮离子的注入剂量低于８×１０１４ｉｏｎｓ／ｃｍ２时，Ｄ．ｒａｄｉｏｄｕｒａｎｓ中ＳＯＤ活性变化不大，当剂量在８×１０１４～６０×１０１４ｉｏｎｓ／ｃｍ２范围内时，ＳＯＤ的活性随着注入剂量的增大逐渐提高，但大于６０×１０１４ｉｏｎｓ／ｃｍ２时，则逐渐下降；加入对不同金属辅基的ＳＯＤ同工酶活性抑制剂Ｈ２Ｏ２和氯仿乙醇的研究表明，中高剂量下氮离子注入诱导的是Ｄ．ｒａｄｉｏｄｕｒａｎｓ中ＭｎＳＯＤ活性的提高，在正常生理条件及小于８×１０１４ｉｏｎｓ／ｃｍ２的剂量下，Ｄ．

Screening and Characterization of the Alkaline Protease Isolated from PLI-1, a Strain of Brevibacillus sp. Collected from Indonesia's Hot Springs

A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia's hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medium (MSM). The extreme thermophile Brevibacillus sp. PLI-1 was found to produce extracellular thermophilic alkaline protease with optimal activity at 70℃ and pH 8.0-9.0. The molecular weight of the protease was estimated to be around 56 kD by SDS-PAGE. The maximum activity of the protease was 26.54 U mL-1. The protease activity did not decrease after 30 min and still retained more than 70% of relative activity after 60 min at 70℃ and pH 8.0. The ion Mg2+ was found to promote protease activity at both low and high concentrations, whereas Cu2+ and Zn2+ could almost completely inhibit the activity. Divalent cation chelator EDTA inhibited the enzyme activity by 55.06% ± 0.27%, while the inhibition caused by PMSF, Leupeptin, Pepstain A and Benzamidine were 66.78% ± 3.25%, 52.37% ± 0.25%, 62.47% ± 2.96% and 50.99% ± 0.24%, respectively. Based on these observations, the enzyme activity was conspicuously sensitive to the serine and cysteine protease inhibitors. All these results indicated that the protease isolated from the strain PLI-1 was a thermophilic protease and had a high-temperature stability and a pH stability.

Cysteine peptidase and its inhibitor activity levels and vitamin E concentration in normal human serum and colorectal carcinomas

AIM: Cysteine peptidase (CP) and its inhibitor (CPI) are a matrix protease that may be associated with colorectal carcinoma invasion and progression, and vitamin E is also a stimulator of the immunological system. Our purpose was to determine the correlation between the expression of cysteine peptidases and their endogenous inhibitors,and the level of vitamin E in sera of patients with colorectal cancer in comparison with healthy individuals.METHODS: The levels of cysteine peptidases and their inhibitors were determined in the sera of patients with primary and metastatic colorectal carcinoma and healthy individuals using fluorogenic substrate, and the level of vitamin E was determined by HPLC.RESULTS: The levels of cysteine peptidases and their inhibitors were significantly higher in the metastatic colorectal cancer patients than that in the healthy controls (P＜0.05).The activity of CP increased 2.2-fold, CPI 2.8-fold and vitamin E decreased 3.4-fold in sera of patients with metastasis in comparison with controls. The level of vitamin E in healthy individuals was higher, whereas the activity of cysteine peptidases and their inhibitors associated with complexes was lower than that in patients with cancer of the digestive tract.CONCLUSION: These results suggest that the serum levels of CP and their inhibitors could be an indicator of the prognosis for patients with metastatic colorectal cancer. Vitamin E can be administered prophylactically to prevent digestive tract neoplasmas.

Effect of Dopamine Injection on the Hemocyte Count and Prophenoloxidase System of the White Shrimp Litopenaeus vannamei

Effects of dopamine injection on the hemocyte count, phenoloxidase activity, serine proteinase activity, proteinase in-hibitor activity and α2-macroglobulin-like activity in L. vannamei were studied. Results showed that dopamine injection resulted in a significant effect on the parameters measured (P < 0.05), while no significant difference was observed in the control group (0.85% NaCl). In the experimental groups,the hemocyte count reached the minimum in 3 h;granular and semi-granular cells became stable after 12 h and hyaline cells and the total hemocyte count became stable after 18 h. Phenoloxidase activity reached the minimum in 6 h, and then became stable after 9 h. Serine protease activity and proteinase inhibitor activity reached the minimum in 3 h, and α2-macro-globulin-like activity reached the maximum in 3 h,and all the three parameters became stable after 12 h. The results suggest that the activating mechanisms of the proPO system triggered by dopamine are different from those triggered by invasive agents or sponta-neously activated under a normal physical condition.

Effect of Calpain inhibitor I on glucocorticoid receptor-dependent degradation and its transactivation ability

Objective: To investigate the effect of Calpain inhibitor I on glucocorticoid receptor-dependent proteasomal degradation and its transcriptional activity. Methods: After Raw-264.7 cells were treated with Calpain inhibitor I, dexamethasone, or both for about 12 h, the change of glucocorticoid receptor was detected by western blot analysis. COS-7 cells were transfected with PRsh-GRα expression vector and glucocorticoid-responsive receptor pMAMneo-CAT, then the effect of Calpain inhibitor I on glucocorticoid receptor transcriptional activation ability was determined by CAT activity. Results: The glucocorticoid receptor levels decreased after RAW-264.7 cells were treated with dexamethasone for 12 hours, which effect can be inhibited by Calpain inhibitor I to some extent. CAT activity assay showed that Calpain inhibitor I enhance glucocorticoid receptor transcriptional activity. Conclusion: Calpain inhibitor I can inhibit the down-regulation of dexamethasone on glucocorticoid receptor, and enhances glucocorticoid receptor transactivation ability.

Effect of germination on the nutritional quality of Pearl millet

Changes in proximate composition, trypsin inhibitor activity, phytic acid, tannins, in vitro protein digestibility and amino acids content of Pearl millet were investigated after germination for 5 days. Germination significantly increased protein content of pearl millet, with a parallel decrease in lipid and carbohydrates. Trypsin inhibitor activity and the phytic acid content showed significant decrease whereas tannin content increased after 5 days germination. In vitro protein digestibility （IVPD） was significantly decreased with germination, suggesting that tannins may be responsible for enzymes inhibition. Amino acid analysis revealed significant increase in essential amino acids and none essential amino acids.

FR167653,a p38 mitogen-activated protein kinase inhibitor,aggravates experimental colitis in mice

AIM: To investigate the effects of FR167653 on the development of dextran sulfate sodium (DSS)-induced colitis in mice. METHODS: BALB/c mice were fed rodent chow containing 3.5% (wt/wt) DSS. The recipient mice underwent intra-peritoneal injection of vehicles or FR167653 (30 mg/kg per day). The mice were sacrificed on day 14, and the degree of colitis was assessed. Immunohistochemical analyses for CD4+ T cell and F4/80+ macrophage infiltration were also performed. Mucosal cytokine expression was analyzed by RT-PCR. RESULTS: The body weight loss was more apparent in the FR167653-treated DSS mice than in the vehicle- treated DSS mice. The colon length was shorter in the FR167653-treated DSS mice than in the vehicle-treated DSS mice. Disease activity index and histological colitis score were significantly higher in FR167653- than in vehicle-treated DSS animals. Microscopically, mucosal edema, cellular infiltration (CD4 T cells and F4/80 macrophages), and the disruption of the epithelium were much more severe in FR167653-treated mice than in controls. Mucosal mRNA expression for interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were found to be markedly reduced in FR167653-treated DSS mice. CONCLUSION: Treatment with FR167653 aggravated DSS colitis in mice. This effect was accompanied by a reduction of mucosal IL-1β and TNF-α expression, suggesting a role of p38 mitogen-activated protein kinase (MAPK)-mediated proinflammatory cytokine induction in host defense mechanisms.

Effects of p38 MAPK inhibitor on the rat pain behavior and proinflammatory cytokines in a metastatic bone cancer pain model

Objective： To observe the effects of p38 mitogen activated protein kinase （MAPK） inhibitor SB203580 by intrathecal injection on the pain behavior and the spinal proinflammatory cytokines in a rat model of bone cancer pain induced by breast cancer cells. Methods： Eleven rats were used to establish the models of bone cancer pain, six rats were treated by intrathecal SB203580 injection, and the other 5 were as the controls. The paw withdrawal latency （PWL）, histology and the spinal levels of IL-1β and TNF-α were detected. Results： All the 11 rats presented evident bone destruction and thermal hyperalgesia after intra-tibial injection of breast cancer cells. No effect of SB203580 on the bone destruction was observed. However, following intrathecal injection of SB203580, the left PWLs （12.12± 1.26 s at 16 days and 12.99 ± 1.65 s at 19 days） were significant higher than that of controls （9.05 ± 1.08 s at 16 days and 8.55 ± 1.60 s at 19 days）, P 〈 0.05. Meanwhile, inkathecal injection of SB203580 evidently reduced the levels of spinal IL-1β and TNF-α. Conclusion： Intrathecal injection of SB203580 in a rat model of bone cancer pain cannot prevent the tibial destruction but significantly depress the thermalgia sensitivity, which might result from inhibiting inkacellular p38 MAPK signaling transduction, and thereby reducing the release of the proinflammatory cytokines.

Prognostic factors to predict survival in non-small-celllung cancer with brain metastasis

Objective: The purpose of the study was to assess prognostic factors to predict overall survival(OS) and progression-free survival(PFS) in non-small-cell lung cancer(NSCLC) with brain metastasis(BM). Methods: From November 2011 to March 2013, the clinical data of 31 NSCLC cases with BM treated with multiple modalities including brain radiotherapy alone, systemic chemotherapy, whole brain radiotherapy(WBRT) combined with tyrosine kinase inhibitor(TKIs). The efficacy and adverse reaction were evaluated after treatment. Results: In terms of intracranial lesions, the objective response rate(ORR) and the disease control rate(DCR) were 22.6% and 90.3%, respectively. As for systemic disease, ORR and DCR were 32.3% and 93.5%, respectively. The median time to progression-free survival(PFS) was 298 days(95% CI: 258.624–337.376 days), whereas in the epidermal growth factor receptor(EGFR) mutation patients was 331 days. Patients who received EGFR-TKIs combined with brain radiation had better response rate(RR) than those only brain radiation. Univariate analysis showed that the EGFR-mutations could predictive factors for PFS, and not to other clinical pathological features. The most common toxicities were rash and diarrhea, but all were well-tolerated. Conclusion: EGFR-mutations is the independent prognostic factors affecting the survival rates of NSCLC patients with BM. Through the clinical observation, icotinib combined with WBRT may be effective on brain metastases in NSCLC patients, and toxicities are tolerable, which worth further study.

The Effectiveness of Watermelon Endocarp Extract in Inhibiting Lipase Activity Relative to the Hypolipidemic Drugs

In the effort to prove the effectiveness of watermelon endocarp extract as a hypolipidemic, the authors have done an initial experiment of lipase inhibition with the extract. The puposes of this study are to evaluate： （1） the optimum condition of lipase in the pankreoflat tablet, （2） the effect of watermelon endocarp extract in inhibition the lipase activity, and （3） the effectiveness of watermelon endocarp extract as lipase inhibitor relative to the hypolipidemic drugs （orlistat）. Watermelon endocarp was extracted by blender, squeezed and filtered. As a source of lipase has been used pankreoflat （Kimia Farina） tablet, inhibition test was performed by mixing 35 mL with substrate （olive oil） that has been coupled with one tablet （0.25 g） ofpankreoflat and extract of 50 g watermelon endocarp and then incubated at 37℃, pH 7.5 for 25 minutes. Lipase activity is indicated by the amount ofNaOH titrant which was used to neutralize the free fatty acid from hydrolysis of olive oil. The results showed that 50 g of watermelon endocarp can produce 26 mL extract and decrease the lipase activity by 70.34%, or equivalent to 85% of the effectiveness of one tablet orlistat （120 mg）, one of the hypolipidemic drugs.

Nutritional Composition and Topoisomerase Inhibitor Activity of Ethnomedicinal Marine Mollusk Nerita albicilla

DNA topoisomerases （topo） I and II are molecular targets of several potent anticancer agents. Thus, inhibitors of these enzymes are potential candidates for anticancer development. Traditionally, Nerita albicilla had been used in Kei Island, Southern Maluku, Indonesia to treat liver disease including cancer. The paper reports on the chemical composition ofNerita albicilla and its topo I inhibitor ofhexane, ethyl acetate and methanol extracts. Topoisomerase-I inhibitor activity was determined using the method reported by TopoGEN. The proximate analysis described that Nerita albicilla dried powder contained 12.45% ± 0.05% moisture; 9.17% ± 0.03% ash; 62.05% ± 0.10% protein; 5.58% ± 0.08% fat; 6.60% ± 0.02% crude fiber and 4.15% ± 0.24% carbohydrate （by difference）. Furthermore, the protein consisted of 11 essential amino acids and six non-essential amino acids. It contained significant amount of branched-chain amino acids （BCAA） valine, leucine, isoleucine （a total of 187.8 mg g-1 protein） and lower content of aromatic amino acids phenylalanine, tyrosine and histidine （a total of 111.26 mg .g-1 protein）. The protein score was 92.2. The yield of hexane, ethyl acetate and methanol extracts ofNerita albicilla were 2.05% ± 0.05%, 1.56% ± 0.06% and 6.99% ± 0.14%, respectively. All extracts showed topoisomerase-I inhibitor activities. Minimum inhibitory concentration （MIC） of methanol extract was 2.50 ug mL-1. Chemical screening of the extracts showed that they contained steroidal and alkaloid compounds. The investigation revealed that Nerita albicilla contains active compounds that could be potential for nutraceutical or pharmaceutical development.

New antiglycation and enzyme inhibitors from Parmotrema cooperi

Lichens are unique individuals which have been widely used in traditional medicines. This study was focused on the bioassayguided phytochemical investigation, and bioactivity evaluation on a lichens species, Parmotrema cooperi. This first bioassaydirected chemical study on P. cooperi has led to the isolation of ethyl heamatomate （1）, atraric acid （2）, ethyl orsellinate （3）, orsellinic acid （4）, lecanoric acid （5）, gyrophoric acid （6）, and licanorin （7）. The structures of 1-7 were mainly elucidated from spectroscopic methods including 1D, and 2D NMR spectroscopy, and mass spectrometry. These compounds were evaluated for their antiglycation, urease, a-chymotrypsin, and β-glucoronidase inhibitory activities. Few of the phenolic compounds showed significant, while most of them showed good inhibition of protein glycation, and urease activities.

THE QSAR RESEARCH ON AURONE INHIBITORS OF HEPATITIS C VIRUS RNA-DEPENDENT RNA POLYMERASE BY APPLYING MULTI-DIMENSIONAL SCALING METHOD

In this paper, we take naturally occurring 2-benzylidenebenzofuran-3-ones （aurones） inhibitors of hepatitis C virus （HCV） RNA-dependent RNA polymerase （RdRp） as an example to study the Multi-dimensional scaling （MDS） method for structure-activity relationship. By analyzing training set molecules, our MDS method combined with a PROXSCAL algorithm can predict inhibitory activity of most compounds correctly. Thus, a new sample＇s activity can be estimated and judged conveniently, and whether it should be synthesized can be known. The MDS method is applicable to optimize the structure for a compound and to provide suggestions for drug design.