全文获取类型
收费全文 | 219篇 |
免费 | 18篇 |
出版年
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 4篇 |
2012年 | 13篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 11篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有237条查询结果,搜索用时 15 毫秒
1.
E Estébanez-Perpi?á A Bayés J Vendrell M A Jongsma D P Bown J A Gatehouse R Huber W Bode F X Avilés D Reverter 《Journal of molecular biology》2001,313(3):629-638
The cotton bollworm Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is one of the most serious insect pests in Australia, India and China. The larva causes substantial economical losses to legume, fibre, cereal oilseed and vegetable crops. This pest has proven to be difficult to control by conventional means, mainly due to the development of pesticide resistance. We present here the 2.5 A crystal structure from the novel procarboxypeptidase (PCPAHa) found in the gut extracts from H. armigera larvae, the first one reported for an insect. This metalloprotease is synthesized as a zymogen of 46.6 kDa which, upon in vitro activation with Lys-C endoproteinase, yields a pro-segment of 91 residues and an active carboxypeptidase moiety of 318 residues. Both regions show a three-dimensional structure quite similar to the corresponding structures in mammalian digestive carboxypeptidases, the most relevant structural differences being located in the loops between conserved secondary structure elements, including the primary activation site. This activation site contains the motif (Ala)(5)Lys at the C terminus of the helix connecting the pro- and the carboxypeptidase domains. A remarkable feature of PCPAHa is the occurrence of the same (Ala)(6)Lys near the C terminus of the active enzyme. The presence of Ser255 in PCPAHa instead of Ile and Asp found in the pancreatic A and B forms, respectively, enlarges the S1' specificity pocket and influences the substrate preferences of the enzyme. The C-terminal tail of the leech carboxypeptidase inhibitor has been modelled into the PCPAHa active site to explore the substrate preferences and the enzymatic mechanism of this enzyme. 相似文献
2.
Conformational predictive studies on the activation segment of pancreatic procarboxypeptidases 总被引:1,自引:0,他引:1
M Vilanova F X Avilés J Vendrell E Méndez 《Biochemical and biophysical research communications》1987,149(2):729-734
Little is known about the conformation and evolutionary origin of the activation segment of pancreatic procarboxypeptidases. Analysis of the sequence and secondary structure propensities of these propeptide segments indicate that they contain two regions structurally related to the Ca2+-binding sites of the EF-hand protein family. This proposed homology could explain how (and why) carboxypeptidases developed such long (94 residues) activation peptides. 相似文献
3.
F X Avilés J Vendrell F J Burgos F Soriano E Méndez 《Biochemical and biophysical research communications》1985,130(1):97-103
Automated Edman degradation of monomeric procarboxypeptidases A and B from porcine pancreas shows that their N-terminal regions (from residue 1 to 34-37) present a high degree of sequential homology to each other as well as to other related procarboxypeptidases. Conformational predictions based on these sequences confirm their structural homology and indicate the probable existence of two beta-turns, one beta-chain and a long alpha-helix in them. On the other hand, tryptic peptide maps on a reverse-phase column indicate great sequential similarities (if not identity) between monomeric procarboxypeptidase A and the procarboxypeptidase A subunit isolated from its binary complex with proproteinase E. 相似文献
4.
Jrme Pne Batrice Lagier Agns Rivier Pascal Chanez Jean-Pierre Vendrell Jean Bousquet 《Cell biology international》1993,17(3):353-358
Establishment of T cell clones derived from bronchial biopsies and peripheral blood from allergic asthmatics has shown that they secret a different IL-4 and IFN-γ pattern of cytokines, suggesting that the micro-environment of the bronchi may influence the phenotype of the T cells. 相似文献
5.
6.
Litman GW; Rast JP; Shamblott MJ; Haire RN; Hulst M; Roess W; Litman RT; Hinds- Frey KR; Zilch A; Amemiya CT 《Molecular biology and evolution》1993,10(1):60-72
Immunoglobulins are encoded by a large multigene system that undergoes
somatic rearrangement and additional genetic change during the development
of immunoglobulin-producing cells. Inducible antibody and antibody-like
responses are found in all vertebrates. However, immunoglobulin possessing
disulfide-bonded heavy and light chains and domain-type organization has
been described only in representatives of the jawed vertebrates. High
degrees of nucleotide and predicted amino acid sequence identity are
evident when the segmental elements that constitute the immunoglobulin gene
loci in phylogenetically divergent vertebrates are compared. However, the
organization of gene loci and the manner in which the independent elements
recombine (and diversify) vary markedly among different taxa. One striking
pattern of gene organization is the "cluster type" that appears to be
restricted to the chondrichthyes (cartilaginous fishes) and limits
segmental rearrangement to closely linked elements. This type of gene
organization is associated with both heavy- and light-chain gene loci. In
some cases, the clusters are "joined" or "partially joined" in the germ
line, in effect predetermining or partially predetermining, respectively,
the encoded specificities (the assumption being that these are expressed)
of the individual loci. By relating the sequences of transcribed gene
products to their respective germ-line genes, it is evident that, in some
cases, joined-type genes are expressed. This raises a question about the
existence and/or nature of allelic exclusion in these species. The
extensive variation in gene organization found throughout the vertebrate
species may relate directly to the role of intersegmental
(V<==>D<==>J) distances in the commitment of the individual
antibody-producing cell to a particular genetic specificity. Thus, the
evolution of this locus, perhaps more so than that of others, may reflect
the interrelationships between genetic organization and function.
相似文献
7.
8.
9.
Isolation and re-association of the subunits from the pro-(carboxypeptidase A)–pro-(proteinase E) binary complex from pig pancreas 下载免费PDF全文
Josep Vendrell Francesc X. Aviles Blanca San Segundo Claudi M. Cuchillo 《The Biochemical journal》1982,205(2):449-452
The component subunits of the pro-(carboxypeptidase A)–pro-(proteinase E) binary complex from pig pancreas were separated with a high recovery (80–95%) of their original potential activity. The isolated subunits and the reconstituted complex have properties similar to those of the corresponding natural species. The tryptic activation course of the pro-(carboxypeptidase A) subunit is substantially modified when bound to pro-(proteinase E), whereas the activation of pro-(proteinase E) is not dependent on this association. 相似文献
10.
Procarboxypeptidases are the remaining major digestive zymogens the activation process of which remains unsolved. Here it is shown that in the tryptic activation of monomeric procarboxypeptidase A from porcine pancreas, the generation of carboxypeptidase A (CPA) activity parallels the limited proteolysis of the 94-residue activation segment. This degradation proceeds from the COOH-terminal end of the molecule, and CPA itself makes an important and unexpected contribution by excising the COOH-terminal arginine residue of the released primary activation fragment. Successive cleavages at some of the peptide bonds of the activation segment nearest to the COOH terminus were found to be of prime importance in eliciting CPA activity, particularly those involving the carbonyl groups of Arg94 and Gly93 which were first cleaved. It is also shown that the rate of activation does not depend directly upon the generation of CPA-alpha and its conversion to CPA-beta. 相似文献