Differences in glycosylation pattern of human secretory ribonucleases.

The major secretory ribonuclease (RNase) of human urine (RNase HUA) was isolated and sequenced by automatic Edman degradation and analysis of peptides and glycopeptides. The isolated enzyme was shown to be free of other urine RNase activities by SDS/polyacrylamide-gel electrophoresis and activity staining. It is a glycoprotein 128 amino acids long, differing from human pancreatic RNase in the presence of an additional threonine residue at the C-terminus. It differs from the pancreatic enzyme in its glycosylation pattern as well, and contains about 45 sugar residues. Each of the three Asn-Xaa-Ser/Thr sequences (Asn-34, Asn-76, Asn-88) is glycosylated with a complex-type oligosaccharide chain. Glycosylation at Asn-88 has not been observed previously in mammalian secretory RNases. Preliminary sequence data on the major RNase of human seminal plasma have revealed no difference between it and the major urinary enzyme; their similarities include the presence of threonine at the C-terminus. The glycosylation pattern of human seminal RNase is very similar to that of the pancreatic enzyme. The structural differences between the secretory RNases from human pancreas, urine and seminal plasma must originate from organ-specific post-translational modifications of the one primary gene product. Detailed characterization of peptides and the results of gel filtration of tryptic and tryptic/chymotryptic digests of performic acid-oxidized RNase have been deposited as Supplementary Publication SUP 50146 (4 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1988) 249, 5.     

切断鸣管神经支对红嘴相思鸟鸣声的影响

该研究以红嘴相思鸟(Leiothrix lutea)为材料,分析对其鸣管神经支(NXIIts)进行断单侧和断双侧处理后的鸣声声学变化,探讨鸣管神经支配特性。结果表明,断单侧NXIIts后红嘴相思鸟均可发出常见叫声,但鸣声音节间隔拉长,音节时程缩短,调频指数下降,且断左侧NXIIts的作用效果明显大于断右侧NXIIts。即NXIIts支配具单侧性,且呈左侧优势,此外,左侧NXIIts还具有产生音节高频成分和谐波的作用。断双侧NXIIts后,红嘴相思鸟鸣声音调唯一,响度大幅下降,音节脉冲数增加。     

中药益智的化学成分研究

采用正反相硅胶、Sephadex LH-20凝胶、MCI树脂等层析技术从中药益智95%乙醇提取物的乙酸乙酯部位分离得到13个化合物,运用现代波谱技术分别鉴定为:益智酮甲(1,yakuchinone A)、益智醇(2,oxyphyllacin-ol)、白杨素(3,chrysin)、rhamnocitrin(4)、oxyphyllenodiol A(5)、oxyphyllenodiol B(6)、nootkatone(7)、dehydro-noot-katone(8)、7-epi-teucrenone(9)、oxyphyllenone A(10)、oxyphyllenone B(11)、原儿茶酸(12,protocatechuic acid)和琥珀酸(13,succinic acid)。其中化合物4、13为首次从该植物中分得,化合物8为新的天然产物。     

脑啡肽-干扰素α-m融合蛋白外用治疗单纯疱疹病毒感染

为探讨脑啡肽-干扰素α-m融合蛋白(EI)外用治疗单纯疱疹病毒感染的作用,分别用HSV-1感染兔子角膜、HSV-2感染豚鼠阴道建立动物感染模型.兔子角膜感染24h后用融合蛋白滴眼液治疗,每天3次,每次0.5ml,共14天.豚鼠阴道感染48h后,用融合蛋白涂剂抹外阴病灶,每天3次,每次10mg,共14天.用IFNα-m和生理盐水/赋形剂作为对照.采用记录病损程度分级法进行临床症消减观察,并于治疗前后测定实验动物病灶病毒滴度、HSV抗体滴度及NK细胞活性.结果显示:与IFNα-m相比,EI治疗组实验动物病毒感染症状大幅减轻且病程缩短,动物病灶中病毒滴度下降,抗HSV抗体滴度升高,NK细胞活性增强.说明脑啡肽干扰素融合蛋白具有较强的消除炎症和局部抗病毒作用,可用于治疗HSV感染引起的疾病.     

Estimating Fundamental Host Range: a Host-Specificity Study of a Potential Biocontrol Agent for Prosopis Species (Leguminosae)

One approach to predicting non-target attack by potential biological control agents is to first describe their fundamental host ranges and then to predict how it will be expressed under postrelease field conditions. In this paper, we illustrate how the fundamental host range can be estimated experimentally by excluding possible limiting factors such as time-dependent effects. The example we use is a host-specificity study of a leaf-tying moth (Gelechiidae: Evippe sp. #1) which was being assessed for the biological control of mesquite (Leguminosae: Prosopis spp.) in Australia. Females oviposited all eggs on plants, mostly into cracks and fissures. First instar larvae leaf-mined and subsequent instars leaf-tied. Oviposition was not host-specific in cage trials, although ten times more eggs were laid on Prosopis than on non-targets. The fundamental host range for initiation of larval feeding was restricted to Prosopis and Leucaena leucocephala which both belong to the same tribe, and the fundamental host range for complete larval development was restricted to Prosopis . We predict that if released in Australia Evippe sp. #1 will only attack Prosopis spp., although low levels of 'indiscriminate' oviposition might occur on other taxa, and might result in initiation of feeding on L. leucocephala .     

银中杨树叶化学成分研究

采用硅胶柱色谱等分离方法,对银中杨Populus alba X P.berolinensis L.树叶的化学成分进行分离纯化,依据理化性质及波谱数据分析进行结构鉴定,从中分离鉴定了12个单体化合物,分别为:邻苯二酚(1),苯甲酸(2),水杨醇(3),东莨菪素(4),咖啡酸(5),水杨酸(6),2’-苯甲酰水杨苷(7),水杨苷(8),丁二酸(9),特里杨苷(10),3’-苯甲酰水杨苷(11)和6’-苯甲酰水杨苷(12),其中化合物3,4,7,9～12为首次从该植物中分离得到。     

Photosystem II solubilizes as a monomer by mild detergent treatment of unstacked thylakoid membranes*

We studied the aggregation state of Photosystem II in stacked and unstacked thylakoid membranes from spinach after a quick and mild solubilization with the non-ionic detergent n-dodecyl-α,D-maltoside, followed by analysis by diode-array-assisted gel filtration chromatography and electron microscopy. The results suggest that Photosystem II (PS II) isolates either as a paired, appressed membrane fragment or as a dimeric PS II-LHC II supercomplex upon mild solubilization of stacked thylakoid membranes or PS II grana membranes, but predominantly as a core monomer upon mild solubilization of unstacked thylakoid membranes. Analysis of paired grana membrane fragments reveals that the number of PS II dimers is strongly reduced in single membranes at the margins of the grana membrane fragments. We suggest that unstacking of thylakoid membranes results in a spontaneous disintegration of the PS II-LHC II supercomplexes into separated PS II core monomers and peripheral light-harvesting complexes. This revised version was published online in June 2006 with corrections to the Cover Date.     

孢子丝菌复合体分子分型研究进展

孢子丝菌复合体属于双相真菌,全球分布,可引起人类及动物的慢性深部感染。不同地域的菌株在致病力、传播途径及药物敏感性等方面均存在差异。孢子丝菌病作为一种人兽共患病,其发病率逐年上升,出现多次暴发流行。分子分型不仅是明确感染源和传播途径、预防和控制疾病流行的有力手段,同时有助于了解孢子丝菌基因型与表型的相关性,在研究其致病机制以及临床诊治过程中都具有十分重要的意义。本文对孢子丝菌的分子分型方法的研究进行综述。     

草甘膦对空心莲子草叶甲Agasicles hygrophila成虫3种代谢酶活性的影响

采用不同浓度的草甘膦0.41 g/L、0.82 g/L、1.23 g/L、1.64g/L、2.05 g/L分别以胃毒和触杀法处理空心莲子草叶甲Agasicles hygrophila成虫,测定其乙酰胆碱酯酶(AChE)、羧酸酯酶(CarE)和谷胱甘肽S-转移酶(GSTs)比活力.试验结果表明:两种处理,草甘膦对AChE活力均有不同程度的抑制作用;对CarE活力影响较为显著,在2.05 g/L浓度下,胃毒处理CarE对α-乙酸萘酯(α-NA)和β-乙酸萘酯(β-NA)水解能力分别是对照组的50%和57%,触杀处理CarE对α-乙酸萘酯(α-NA)和β-乙酸荼酯(β-NA)水解能力分别是对照组的53%和59%;胃毒处理埘酶活力影响大于触杀处理,草甘膦对GSTs的活力影响不明显.     

α-突触核蛋白的细胞毒性作用

神经系统变性疾病的一个重要特征就是α-突触核蛋白功能障碍,形成含有α-突触核蛋白的胞质包含体。虽然对α-突触核蛋白损伤神经系统的作用做了大量的研究,但其神经毒性机制尚不清楚。该文从α-突触核蛋白的结构、生理功能及其对泛素-蛋白酶体、线粒体、内质网及高尔基体等的毒性作用方面介绍近年来对其的研究进展。