孔石莼(Ulya pertusa)凝集素的分离纯化及性质的研究

为抑制肿瘤细胞增殖和防治有关病害提供基础理论依据,将孔石莼(Ulva pertusa)经磷酸盐缓冲液抽提,20%～75%硫酸铵分级沉淀,牛甲状腺球蛋白-Sepharose 4B亲和层析,可以从绿藻孔石莼中纯化出孔石莼凝集素(UPL),在PAGE上显示单一蛋白染色带,在等电聚焦电泳上显示单一蛋白染色带,其pI为8.40.纯化后的UPL的最大紫外吸收峰在285 nm,用Sephadex G-200分子筛层析测得其分子量为11 047.该凝集素可以凝集人的A、B、AB、O型红细胞,且凝集活性相同,在对人(A、B、AB、O)兔、鲤、鲫的红细胞的凝集作用中,兔的凝集作用最强.该凝集素凝集兔红细胞的作用不被D-半乳糖、D-果糖、葡萄糖、蔗糖、甘露聚糖、γ球蛋白、卵清蛋白所抑制,仅被牛甲状腺球蛋白抑制,最小抑制浓度为6.20 g/L.该凝集素在pH4.0～10.14范围内均有活性,但在pH6.50～9.51范围内活性较高,该凝集活性在85℃加热1 h,活力仍未改变,说明具有很强的耐热性.     

孔石莼(Ulva pertusa)质体蓝素基因的克隆及基因特征分析(英文)

采用cDNA末端快速扩增的办法,从孔石莼(Ulva pertusa)中克隆获得质体蓝素基因。该基因完整的cDNA为787bp,包括40 bp 5’端非编码区和327 bp的3’端非编码区,以及一个420 bp的开放阅读框架,编码139个氨基酸的蛋白质。该基因编码质体蓝素的前体肽,其N端41个氨基酸残基为信号肽,后面为98个氨基酸残基的成熟肽。从Genbank中选择了13个质体蓝素的前体肽基因进行序列比对分析和构建进化树。孔石莼质体蓝素基因与其它质体蓝素基因的同源性为48.2%至78.8%。该进化树将来源于6种藻类植物的7个质体蓝素基因聚类在一起,显示出它们较近的进化关系。同样,也表现出11种生物的分子进化关系。序列比对结果显示,在质体蓝素的基因序列中存在两个高度保守的基序,它编码质体蓝素蛋白的铜结合活性位点。     

盐度、光照和营养盐对孔石莼(Ulva pertusa)光合作用的影响

通过测定光合作用产氧速率研究了孔石莼Ulvapertusa不育性变种在不同盐度、光强度和营养盐水平下的光合作用特性.结果表明,盐度可影响光合作用速率,在2710lx光强下孔石莼在盐度20‰左右有最大光合作用速率;光合作用参数Pm为79.62O2,μg/cm2*h,Is为191.08μE/m2*s,IC为10.12μE/m2*s;对营养盐(NH4+-N,NO2--N,PO43--P)的吸收特征可用Michaelis-Menten方程描述,低光强(106lx)下氨氮超过0.07mmol/L时可抑制孔石莼的光合作用.     

桑寄生凝集素的纯化及部分性质研究

利用DEAE一纤维素柱盐离子浓度梯度洗脱,再经猪胃粘蛋白-Sepharose 4 B亲和柱可以从中药桑寄生中分离纯化出桑寄生凝集素。经pH8.9,Tris-EDTAN_2a-borate的PACE和SDS-PAGE测定均呈现单一蛋白带,测得其分子量为67 500,中性糖含量为14.6％,DNS法测得N-末端氨基酸为缬氨酸。氨基酸组成分析表明,该凝集素富含酸性氨基酸,而碱性氨基酸含量较少,不含精氨酸。当凝集素浓度为15.6μg/mL时,即可凝集兔红细胞,而对人的A、B、O型血细胞,凝集素浓度高达1000μg/mL,也不发生凝集反应。Gal、GalNAc、山梨糖、岩藻糖和松三糖对凝集兔红细胞的能力有抑制作用。桑寄生凝集素是一种促有丝分裂原,对猪血淋巴细胞的转化率达78％,细胞分裂比率为11.2％。     

鸡Zong凝集素的分离纯化与性质研究

鸡Ｚｏｎｇ菌丝体浸取液依次经硫酸铵分级沉淀,ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ ＣＬ－６Ｂ离子交换层析和Ｓｅｐｈａｄｅｘ Ｇ－１００分子筛层析３个主要步骤纯化得到一种凝集素（ＴＡＬ）。纯化的ＴＡＬ在聚丙烯酰胺凝胶电泳上显示一条蛋白质着色带。ＴＡＬ的分子量为８９．４ｋＤ,亚基分子量为３８ｋＤ和５１ｋＤ,提示ＴＡＬ分子由两个不同亚基组成。ＴＡＬ具有供血动物种属专一性,使Ｗｉｓｔａｒ大鼠红细胞凝集所需ＴＡＬ最     

紫藤凝集素的分离纯化及理化性质研究

用常规方法处理的ＤＥＡＥ离子交换纤维素柱,通过线性离子强度梯度洗脱,从紫藤种子的蛋白粗提液中得到一定纯度的紫藤凝集素。纯化的凝集素凝集兔红血球的比活提高４０倍,总活力回收率为１９．２％。紫藤凝集素的分子量经ＰＡＧＥ鉴定为２０５ｋｄ,是由两种亚基构成的四聚体,这两种亚基各有２个,分子量ＳＤＳ－ＰＡＧＥ鉴定分别为７７６００ｄ和２５１００ｄ。紫藤凝集素是一种糖蛋白,等电点约为４．６０。它可凝集人的各种血     

BACTERIA THAT INDUCE MORPHOGENESIS IN ULVA PERTUSA (CHLOROPHYTA) GROWN UNDER AXENIC CONDITIONS1

Marine foliaceous green macroalgae such as Ulva lose their typical morphology when cultured aseptically in defined synthetic media. However, after reinfection by certain marine bacteria (isolated from unialgal cultures of Ulva pertusa Kjellman), the organisms regain their typical foliaceous or tubular morphology. To investigate the morphogenesis (MG) induced in U. pertusa by bacteria, we isolated and identified bacteria with MG activity on U. pertusa and studied the distribution of such bacteria in seawater and on various marine macroalgae. We isolated 1555 bacterial strains from 18 species of marine macroalgae (six Chlorophyta, five Phaeophyta, and seven Rhodophyta), from seawater and from sediment collected at the beach at Omaezaki, Shizuoka Prefecture; Japan. Of these, 676 bacterial strains (43.5%) showed MG activity. They were classified into six bacterial groups, Flavobacterium, Vibrio, Pseudomonas, Deleya, Escherichia, and gram-positive cocci. These bacteria were ubiquitous among the samples and were not specific to U. pertusa. Several plant growth regulators had no MG activity. Filter-sterilized supernatants of culture media of MG-active bacteria strains did not induce MG. Cocultivation of Ulva with active bacterial strains is so far the only way to induce the MG effect, which suggests that for MG direct contact between Ulva and the bacterial strain is necessary.     

连续性干出对孔石莼生长和生化组成的影响

以孔石莼(Ulva pertusa)为试验材料,研究了连续性干出对其生长和生化组成的影响.结果表明:与对照组(0 h)相比,短时间的连续性干出促进孔石莼生长,表现在特定生长率( SGR)升高、叶绿素a含量上升;随着连续性干出时间延长,孔石莼SGR、叶绿素a、蛋白质含量下降,叶绿素b、可溶性糖含量上升;叶绿素a/b比值变化和可溶性糖含量变化有利于抵抗干出胁迫.     

The induction of reproductive cell formation of Ulva pertusa Kjellman (Ulvales, Ulvophyceae)

Synchronous zooid formation in Ulva pertusa Kjellman was induced in excised disks maintained in sterilized seawater at 20°C, 12:12 h L:D cycle and fluorescent light at 100 μmol photons m ²s ¹. Zooids were reieased from mature disk tissue on the morning of the second or the third day after excision. The degree of zooid formation was found to be dependent on disk size and the region of the mother thalius from which the disk tissue was excised. Zooid formation was induced in more than 90% of small disks (0.9 mm in diameter) which were taken from the margins of the Ulva thalli. When disks were incubated together with a perforated mother thalius, the disks remained sterile. The presence of maturation inhibitors in vegetative thalli is suggested.     

Requisite Morphologic Interaction for Attachment between Ulva pertusa (Chlorophyta) and Symbiotic Bacteria

In order to understand the morphogenesis-inducing mechanism of Ulva pertusa by symbiotic bacteria, we observed the requisite conditions of bacteria for attachment to U. pertusa for algal morphogenesis. Non-morphogenesis-inducing bacterial mutants derived by ultraviolet irradiation did not attach onto the surface of this alga. Scanning electron microscopic observation during the process of morphogenesis in U. pertusa revealed a network-like structure formed on the algal surface within 1 week after application of bacteria. The bacteria attached onto the alga after 2 weeks of incubation. After this attachment process the morphologic change was observed in U. pertusa. Received August 7, 1997; accepted July 24, 1998.