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941.
MemType-2L: a web server for predicting membrane proteins and their types by incorporating evolution information through Pse-PSSM 总被引:1,自引:0,他引:1
Given an uncharacterized protein sequence, how can we identify whether it is a membrane protein or not? If it is, which membrane protein type it belongs to? These questions are important because they are closely relevant to the biological function of the query protein and to its interaction process with other molecules in a biological system. Particularly, with the avalanche of protein sequences generated in the Post-Genomic Age and the relatively much slower progress in using biochemical experiments to determine their functions, it is highly desired to develop an automated method that can be used to help address these questions. In this study, a 2-layer predictor, called MemType-2L, has been developed: the 1st layer prediction engine is to identify a query protein as membrane or non-membrane; if it is a membrane protein, the process will be automatically continued with the 2nd-layer prediction engine to further identify its type among the following eight categories: (1) type I, (2) type II, (3) type III, (4) type IV, (5) multipass, (6) lipid-chain-anchored, (7) GPI-anchored, and (8) peripheral. MemType-2L is featured by incorporating the evolution information through representing the protein samples with the Pse-PSSM (Pseudo Position-Specific Score Matrix) vectors, and by containing an ensemble classifier formed by fusing many powerful individual OET-KNN (Optimized Evidence-Theoretic K-Nearest Neighbor) classifiers. The success rates obtained by MemType-2L on a new-constructed stringent dataset by both the jackknife test and the independent dataset test are quite high, indicating that MemType-2L may become a very useful high throughput tool. As a Web server, MemType-2L is freely accessible to the public at http://chou.med.harvard.edu/bioinf/MemType. 相似文献
942.
汉坦病毒H8205部分核壳蛋白基因在E.coli中的表达 总被引:1,自引:0,他引:1
根据汉坦病毒H8205株NP基因的序列,设计一对引物,扩增NP前292个氨基酸多肽基因片段,克隆于表达载体pGEX3X,与载体中26kD的谷胱苷肽巯基转移酶(GST)融合表达。SDSPAGE显示表达产物(GSTNP)主要以包涵体形式存在。Westernbloting表明此融合蛋白有抗原性。包涵体经分离、洗涤、溶解后,Sepharose6B层析纯化,用此融合蛋白作抗原,进行ELISA法检测临床HFRS病人标本的IgG和IgM,有很好的特异性和敏感性。有生物活性的汉坦病毒H8205NP的体外表达成功,为汉坦病毒基因工程抗原的大量制备奠定了基础,也为汉坦病毒的临床检测和流行病学调查提供了一种廉价、安全、可靠的抗原。 相似文献
943.
本文对陕西泾阳地区冬小麦田净辐射进行了分段和分层模拟,取得了较好的拟合效果,相对误差在10%以内。确定了麦田相对叶面积函数最大值的出现高度为4.5/7H,介于高粱(4/7H)和谷子(5/7H)之间。计算了不同发育期、不同层次至冠层顶部累积叶片的消光系数,结果表明,消光系数因发育期和叶片层次而异,拔节期,由旗叶向下,消光系数增大,乳熟期旗叶的消光系数最大,比拔节期大一倍,倒二叶以上两个层次叶片消光系数较小。就平均而言,冬小麦消光系数拔节期为0.51,乳熟期为0.56。本项成果为进一步开展麦田小气候研究提供了有意义的数据和方法。 相似文献
944.
945.
用中性红标记酵母原生质体初探 总被引:1,自引:0,他引:1
用2%蜗牛酶处理酵母细胞60分钟,啤酒酵母Y29的原生质体形成率为90%,再生率为9.5%;糖化酵母IB的原生质体形成率为86%,再生率为12%。用500ppm中性红染液对Y29菌株的整细胞和原生质体染色15分钟,细胞的着色率为84%,存活率为12%,而原生质体的着色率为75%,再生率为6.4%,经染色后的原生质体体积缩小,在交变电场中排队所需的场强电降低。 相似文献
946.
947.
Han-Yu Wang Yi-Ru Shen Yung-Chieh Tsai Shang-Rung Wu Chia-Yih Wang Pao-Lin Kuo 《Journal of cellular physiology》2023,238(3):597-609
Septin-based ring complexes maintain the sperm annulus. Defective annular structures are observed in the sperm of Sept12- and Sept4-null mice. In addition, sperm capacitation, a process required for proper fertilization, is inhibited in Sept4-null mice, implying that the sperm annulus might play a role in controlling sperm capacitation. Hence, we analyzed sperm capacitation of sperm obtained from SEPT12 Ser196 phosphomimetic (S196E), phosphorylation-deficient (S196A), and SEPT4-depleted mutant mice. Capacitation was reduced in the sperm of both the Sept12 S196E- and Sept12 S196A-knock-in mice. The protein levels of septins, namely, SEPT4 and SEPT12, were upregulated, and these proteins were concentrated in the sperm annulus during capacitation. Importantly, the expression of soluble adenylyl cyclase (sAC), a key enzyme that initiates capacitation, was upregulated, and sAC was recruited to the sperm annulus following capacitation stimulation. We further found that SEPT12, SEPT4, and sAC formed a complex and colocalized to the sperm annulus. Additionally, sAC expression was reduced and disappeared in the annulus of the SEPT12 S196E- and S196A-mutant mouse sperm. In the sperm of the SEPT4-knockout mice, sAC did not localize to the annulus. Thus, our data demonstrate that SEPT12 phosphorylation status and SEPT4 activity jointly regulate sAC protein levels and annular localization to induce sperm capacitation. 相似文献
948.
Le Wang Xiaodong She Guixia Lv Yongnian Shen Qing Cai Rong Zeng Caixia Li Yiping Ge Shuwen Deng G. S. de Hoog Min Li Weida Liu 《Mycopathologia》2013,175(3-4):331-338
We report a case of mucocutaneous phaeohyphomycosis caused by Exophiala spinifera. Crusty plaques and nodules were major clinical features. Histological examination revealed brown yeast-like cells and hyphae. Mycological and molecular data identified E. spinifera as etiologic agent. Oral itraconazole was effective, which was in accordance with the results of in vitro susceptibility testing. We speculated that her pregnancy may play a role of risk factor in the infection by E. spinifera. 相似文献
949.
Meiru Si Lei Zhang Muhammad Tausif Chaudhry Wei Ding Yixiang Xu Can Chen Ali Akbar Xihui Shen Shuang-Jiang Liu 《Applied and environmental microbiology》2015,81(8):2781-2796
Oxidation of methionine leads to the formation of the S and R diastereomers of methionine sulfoxide (MetO), which can be reversed by the actions of two structurally unrelated classes of methionine sulfoxide reductase (Msr), MsrA and MsrB, respectively. Although MsrAs have long been demonstrated in numerous bacteria, their physiological and biochemical functions remain largely unknown in Actinomycetes. Here, we report that a Corynebacterium glutamicum methionine sulfoxide reductase A (CgMsrA) that belongs to the 3-Cys family of MsrAs plays important roles in oxidative stress resistance. Deletion of the msrA gene in C. glutamicum resulted in decrease of cell viability, increase of ROS production, and increase of protein carbonylation levels under various stress conditions. The physiological roles of CgMsrA in resistance to oxidative stresses were corroborated by its induced expression under various stresses, regulated directly by the stress-responsive extracytoplasmic-function (ECF) sigma factor SigH. Activity assays performed with various regeneration pathways showed that CgMsrA can reduce MetO via both the thioredoxin/thioredoxin reductase (Trx/TrxR) and mycoredoxin 1/mycothione reductase/mycothiol (Mrx1/Mtr/MSH) pathways. Site-directed mutagenesis confirmed that Cys56 is the peroxidatic cysteine that is oxidized to sulfenic acid, while Cys204 and Cys213 are the resolving Cys residues that form an intramolecular disulfide bond. Mrx1 reduces the sulfenic acid intermediate via the formation of an S-mycothiolated MsrA intermediate (MsrA-SSM) which is then recycled by mycoredoxin and the second molecule of mycothiol, similarly to the glutathione/glutaredoxin/glutathione reductase (GSH/Grx/GR) system. However, Trx reduces the Cys204-Cys213 disulfide bond in CgMsrA produced during MetO reduction via the formation of a transient intermolecular disulfide bond between Trx and CgMsrA. While both the Trx/TrxR and Mrx1/Mtr/MSH pathways are operative in reducing CgMsrA under stress conditions in vivo, the Trx/TrxR pathway alone is sufficient to reduce CgMsrA under normal conditions. Based on these results, a catalytic model for the reduction of CgMsrA by Mrx1 and Trx is proposed. 相似文献
950.