香菇漆酶同工酶的部分酶学性质的研究

通过丙酮分级沉淀、DEAE-纤维素离子柱层析和Sephadex G100柱层析得到两种香菇漆酶同工酶,分别命名为lac1和lac2,并对其理化性质进行了研究.考察了香菇漆酶同工酶最适反应温度和pH值、热稳定性和pH值稳定性、反应动力学常数以及金属离子对酶活的影响.试验结果表明:Lac1、lac2最适作用温度都为30℃,在不高于40℃的条件下保存30 min,lac1残余酶活在60%以上,lac2在不高于60℃有较高热稳定性,残余酶活在80%以上.最适pH值,lac1为3.6,lac2为4.0.pH值3.0～4.8,lac1有较强稳定性,在pH值4.0～4.6,lac2有较强的稳定性.以邻联甲苯胺为底物lac1和lac2的Km分别为0.964 mmol/L和1.38 mmol/L.金属离子Cl-对lacl有激活作用,Ag 、Mn2 对lac1有抑制作用.金属离子Ba2 和Cu2 对lac2有激活作用,Fe3 、Cl-、Ca2 、Zn2 、Ag 、Mn2 对lac2有抑制作用.     

红芝组成型漆酶酶学性质的研究

研究了温度、pH值、金属离子和抑制剂对红芝漆酶活性和稳定性的影响,测定该漆酶的Km值和Vmax。结果表明:红芝漆酶最适反应温度为60℃,低于50℃时较稳定;最适pH值为3.0,在pH 2.5~4.0的范围表现出较强的稳定性;Cu2+、Mn2+、Mg2+对酶活有促进作用,而Cr3+、Hg2+、Fe2+和抑制剂EDTA、DMSO、SDS对酶活有抑制作用;以愈创木酚为底物时Km值为0.13 mmol/L,最大反应速率Vmax为234 nmol.mL-1.min-1。     

杏鲍菇漆酶的生物学特性

从杏鲍菇、双孢蘑菇、美味侧耳、茶薪菇、凤尾菇和香菇子实体中提取漆酶，用分光光度法测定酶活，发现杏鲍菇漆酶酶活最高，实验结果表明，杏鲍菇漆酶是一种较稳定的高温酶，其最适PH为3．0，最适温度60℃；Pb^2＋,K^ 对酶活有较大的激活使用，而Fe^3 ,Fe^2 则对酶活有较强的抑制作用。     

桑黄漆酶的发酵条件研究初报

采用液体深层培养方法通过不同碳源、氮源、pH值、温度等因素对桑黄产酶量的影响,研究桑黄合成漆酶的最适发酵条件。采用L9(34)正交设计法对桑黄合成漆酶发酵培养基进行了优化,初步筛选出了桑黄合成漆酶发酵培养基。结果表明,培养基为玉米粉1%、麦麸1%、葡萄糖2%、蛋白胨0.5%、酵母膏0.5%、磷酸二氢钾0.1%、硫酸镁0.05%、添加Cu2+浓度60μmol.L-1,维生素B1 1 mg.100-1.mL-1,漆酶产量最高,为7 666 U.L-1。     

香菇中γ-谷氨酰转肽酶的分离纯化及其酶学性质研究

通过(NH4)2SO4沉淀、Phenyl Sepharose FF疏水层析分离纯化香菇中的γ-谷氨酰转肽酶(γ-Glutamyltranspeptidase,GGT),纯化后的GGT的比活力到达了19.59 U/mg.SDS-PAGE分析表明,GGT由分子量分别为28 kDa和60 kDa的两个亚基组成.酶学性质试验结果表明,GGT反应的最适温度为37 ℃,最适pH 值为7.6;金属离子Na+、K+和Ca2+对酶有激活作用,而Ag+、Cu2+、Zn2+和Fe3+则有抑制作用;试验范围内,GGT水解γ-glutamyl-p-nitroanilide的米氏动力学参数Km 值为2.601 μmol/mL,Vmax值为0.0287 μmol/min;组成的氨基酸中,Glu和Asp含量较高,Met和Cys含量较低.     

糙皮侧耳以果皮为基质固态发酵产漆酶及其酶学性质的研究

以漆酶活性为指标,利用不同果皮为基质对糙皮侧耳(Pleurotus ostreatus)固态发酵产漆酶的条件进行优化并对所产漆酶进行纯化,研究纯化后漆酶的酶学性质。结果表明:以柚皮为培养基质(5g柚皮、25mL水、20μL吐温-80),30℃固态发酵10d,糙皮侧耳产漆酶的活性最高,比活力为21800U/g;在该条件下将糙皮侧耳所产漆酶的粗酶液用硫酸铵沉淀、透析、浓缩、DEAE-纤维离子交换柱层析得到漆酶蛋白单一条带,SDS-PAGE检测蛋白相对分子质量约66000;该漆酶命名为Lac h2,其最适反应温度为60℃,最适反应pH值为4.5;在30～50℃,pH 4.5～6.0范围内稳定;金属离子Zn~(2+)、Mn~(2+)、Cu~(2+)和Mg~(2+)对纯化的漆酶Lac h2的酶活力有促进作用而Ca~(2+)、Ag~+和Fe~(2+)对Lac h2的酶活力有抑制作用。     

改良壳聚糖固定化真菌漆酶的研究

以改良壳聚糖-壳聚糖铜为载体,戊二醛为交联剂对真菌漆酶进行了固定化研究,探讨了其固定化条件及固定化酶的部分性质.结果表明:戊二醛最适浓度为0.5%,交联最佳时间14 h,最佳给酶量约1.3 mg,固定时间12 h或0.5 h.在此条件下获得的固定化漆酶酶活回收率分别为56.4%与51.2%.与游离酶相比,固定化漆酶与作用底物邻联甲苯胺的亲和力降低,但固定化漆酶的稳定性有明显改善.最适温度分别为40℃和80℃,分别比游离酶提高10℃和50℃;90℃条件下保温5 h后固定化酶活保留率分别为57.4%和40%,而相同条件下游离酶酶活明显下降.     

营养液pH值对香菇菌丝生物量的影响

香菇是我国生产规模及产量最大的食用菌。pH值是反应菌棒质量及培养条件的重要指标之一,不同种类的食用菌其菌丝生长要求的pH值不同。作者对适宜香菇菌丝生长的pH值范围开展了试验研究。试验结果表明,高温灭菌不仅能有效杀死培养基质中的杂菌,降低菌种接种后的污染率,而且还能引发基质内部养分含量、pH值等的变化;不同的酸性物质对香菇菌丝生长的影响有一定的差异;香菇液体菌丝可在营养液pH值5.0～5.9的范围内生长,最适pH值为5.6,营养液pH值为5.0时菌丝生物量显著降低;用草酸和柠檬酸调节营养液初始pH值时,香菇菌丝生长的适宜pH值范围较广,为5.6～5.9;用酒石酸及磷酸调节营养液初始pH值时,最适pH值为5.6。     

锦橙叶片POD动力学研究

以锦橙成熟春梢叶片提取过氧化物酶 (POD) ,分别测定了该酶的最适pH、最适温度及酶促动力学参数Km值和Vmax值 ,比较分析了常见几种POD抑制剂的作用程度。结果表明 :以邻甲氧基酚为底物 ,叶片POD的最适pH为 5 .0 ,最适温度为 32℃ ,Km值为 2 8.0 4mmol/L ,Vmax值为 147.83unit/s·gFW。在所测的 6种抑制剂 (K+、Pb2 +、CN-、Vc、硫脲及L 半胱氨酸 )中 ,CN-,Pb2 +,硫脲和L 半胱氨酸对POD表现出较强的抑制作用 ,K+对POD活性起促进作用。在一定浓度范围内 ,各种抑制剂的作用程度与其浓度具有极显著的相关性     

木耳漆酶高产菌株筛选及其发酵条件的研究

通过运用不同检测方法对木耳属中的三个种的 2 7个菌株的产过氧化物酶、漆酶能力的检测 ,筛选得到一漆酶高产菌株毛木耳 (Auriculariapolytricha)AP4。并且对AP4的产漆酶的发酵条件进行了初步研究。摇瓶实验产漆酶的最佳培养基的成分为 :碳源羧甲基纤维素(CMC) 5g/L ,氮源NH4NO3 L -天冬酰胺 (L -As paragine) 2 4mmol/L ,培养基的初始pH4 0 ,培养温度2 5℃。     

Effects of radiation from 188Re on smooth muscle cell proliferation

AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β^-particles emission from ¹⁸⁸Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by ¹⁸⁸Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [³H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of ¹⁸⁸Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from ¹⁸⁸ Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G₀/G₁ arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.     

Ergebnisse der Leistungsprüfungen der Süßkirschensorte ‚Stella‘ auf Gisela- und Weiroot-Unterlagen in Bulgarien

Zusammenfassung Die Leistungsprüfungen wurden im Zeitraum 1997 bis 2003 mit den Unterlagen Gisela 4 und 5, den Klonnummern 195/20 und 497/8 aus der Gisela-Serie sowie Weiroot 10, 13, 53, 72 und 158 durchgeführt. Dabei dienten Sämlinge von P1 (bulgarische Selektion aus Prunus mahaleb) als Kontrolle. Alle Unterlagen waren mit der Sorte Stella veredelt und im Dezember 1996 in der Versuchsanlage der Agraruniversität in Plovdiv, Bulgarien, im Abstand von 6 m×4,5 m gepflanzt worden. Dabei erfolgte ein Pflanzschnitt. Nach Abschluss der natürlichen Kronenentwicklung wurde jedes Jahr ein Winterschnitt vorgenommen. Der Boden wurde durch mechanische Bearbeitung offen gehalten und nach dem 4. Standjahr wurden die Baumstreifen mit Herbiziden behandelt. Die Wasserversorgung erfolgte durch eine dem natürlichen Gefälle folgende Überflutung, allerdings nicht immer zum optimalen Zeitpunkt, da keine eigene Wasserquelle zur Verfügung stand.Basierend auf den Ergebnissen bis zum Anfang des 7. Standjahres können die untersuchten Unterlagen in zwei Gruppen differenziert werden: starkwüchsig—Weiroot 10, P1 und Weiroot 13; mittelstarkwachsend bis schwachwüchsig—Gi 497/8, Gisela 4, Weiroot 53, Weiroot 158, Gi 195/20, Weiroot 72 und Gisela 5. Letztere zeichnete sich durch besondere Schwachwüchsigkeit aus. Die meisten Wurzelschosser bildeten Gisela 4, Weiroot 10 und Weiroot 13. Weiroot 53, Weiroot 72 und Weiroot 158 entwickelten deutlich weniger und P1, Gisela 5, Gi 195/20 sowie Gi 497/8 keine Wurzelschosser. Den frühesten Blühbeginn induzierte Gisela 4. Die anderen Unterlagen führten, in Abhängigkeit von den Temperaturbedingungen des jeweiligen Jahres, zu einer Verspätung der Blüte: P1 und Weiroot 10 um 1–2 Tage; Gi 497/8, Weiroot 13 und Weiroot 158 um 2–4 Tage; Weiroot 72 um 2–7 Tage; Gi 195/20 um 3–6 Tage; Weiroot 53 um 3–8 Tage und Gisela 5 um 3–10 Tage. Die Reifezeit der Früchte war bei den Bäumen auf Gisela 5 im Vergleich zu den anderen Varianten um 2–3 Tage verspätet. Gisela 5, Weiroot 72 und Gisela 4 induzierten bei der aufveredelten Sorte die höchsten Ertragsleistungen, P1 die geringsten. Bei den Bäumen auf Gisela 5 war die Fruchtgröße geringer als bei den anderen Unterlagen. Bäume auf Gisela 5 brauchen intensive Pflege. Nur wenn alle Produktionsfaktoren und kulturtechnischen Maßnahmen optimiert werden, kann das hohe Ertragspotenzial dieser Unterlage ausgeschöpft werden.     

Effect of L-Arg on plasma content of endothelin and expression of c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy

AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.     

多效唑对猕猴桃离体试管苗生长及内源激素的影响

多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。     

Proteomic analysis between pathological scars and normal skin

AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.     

Coupling past management practice and historic landscape change on John F. Kennedy Space Center,Florida

Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.     

XBP-01 accelerated apoptosis induced by oxidized low density lipoprotein in vascular smooth muscle cells

AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.     

Metallothionein inhibits homocysteine-induced proliferation of rat vascular smooth muscle cells

AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [³-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10^-6-10^-4 mmol/L) stimulated [³-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [³-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P＜0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P＜0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10^-6-10^-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P＜0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl₂ for 6 h induced an increase cellular MT content by 5.7-fold (P＜0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P＜0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation.