Base de dados : MEDLINE
Pesquisa : D12.776.053.200 [Categoria DeCS]
Referências encontradas : 18 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 2 ir para página        

  1 / 18 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:23079646
[Au] Autor:Kundu S; Roy D
[Ad] Endereço:Bioinformatics Centre, Bose Institute, Kolkata, India.
[Ti] Título:Structural analysis of Ca²âº dependent and Ca²âº independent type II antifreeze proteins: a comparative molecular dynamics simulation study.
[So] Source:J Mol Graph Model;38:211-9, 2012 Sep.
[Is] ISSN:1873-4243
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Comparative molecular dynamics simulations of Ca²âº dependent psychrophilic type II antifreeze protein (AFP) from herring (Clupea harengus) (hAFP) and Ca²âº dependent type II antifreeze protein from long snout poacher (Brachyopsis rostratus) (lpAFP) have been performed for 10 ns each at five different temperatures. We have tried to investigate whether the Ca²âº dependent protein obtains any advantage in nature over the independent one. To this end the dynamic properties of these two proteins have been compared in terms of secondary structure content, molecular flexibility, solvent accessibility, intra molecular hydrogen bonds and protein-solvent interactions. At 298 and 373 K the flexibility of the Ca²âº independent molecule is higher which indicates that Ca²âº could contribute to stabilize the structure. The thermal unfolding pathways of the two proteins have also been monitored. The rate of unfolding is similar up to 373 K, beyond that hAFP shows faster unfolding than lpAFP. The essential subspaces explored by the simulations of hAFP and lpAFP at different temperatures are significantly different as revealed from principal component analysis. Our results may help in understanding the role of Ca²âº for hAFP to express antifreeze activity. Furthermore our study may also help in elucidating the molecular basis of thermostability of two structurally similar proteins, which perform the same function in different manner, one in presence of Ca²âº, and the other in absence of the same.
[Mh] Termos MeSH primário: Proteínas Anticongelantes Tipo II/química
Cálcio/química
Simulação de Dinâmica Molecular
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Temperatura Baixa
Peixes
Ligações de Hidrogênio
Cinética
Dados de Sequência Molecular
Análise de Componente Principal
Dobramento de Proteína
Estabilidade Proteica
Estrutura Secundária de Proteína
Estrutura Terciária de Proteína
Desdobramento de Proteína
Solventes
Especificidade da Espécie
Termodinâmica
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Antifreeze Proteins, Type II); 0 (Solvents); SY7Q814VUP (Calcium)
[Em] Mês de entrada:1304
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:121020
[St] Status:MEDLINE


  2 / 18 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:23009612
[Au] Autor:Graham LA; Li J; Davidson WS; Davies PL
[Ad] Endereço:Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
[Ti] Título:Smelt was the likely beneficiary of an antifreeze gene laterally transferred between fishes.
[So] Source:BMC Evol Biol;12:190, 2012 Sep 25.
[Is] ISSN:1471-2148
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Type II antifreeze protein (AFP) from the rainbow smelt, Osmerus mordax, is a calcium-dependent C-type lectin homolog, similar to the AFPs from herring and sea raven. While C-type lectins are ubiquitous, type II AFPs are only found in a few species in three widely separated branches of teleost fishes. Furthermore, several other non-homologous AFPs are found in intervening species. We have previously postulated that this sporadic distribution has resulted from lateral gene transfer. The alternative hypothesis, that the AFP evolved from a lectin present in a shared ancestor and that this gene was lost in most species, is not favored because both the exon and intron sequences are highly conserved. RESULTS: Here we have sequenced and annotated a 160 kb smelt BAC clone containing a centrally-located AFP gene along with 14 other genes. Quantitative PCR indicates that there is but a single copy of this gene within the smelt genome, which is atypical for fish AFP genes. The corresponding syntenic region has been identified and searched in a number of other species and found to be devoid of lectin or AFP sequences. Unlike the introns of the AFP gene, the intronic sequences of the flanking genes are not conserved between species. As well, the rate and pattern of mutation in the AFP gene are radically different from those seen in other smelt and herring genes. CONCLUSIONS: These results provide stand-alone support for an example of lateral gene transfer between vertebrate species. They should further inform the debate about genetically modified organisms by showing that gene transfer between 'higher' eukaryotes can occur naturally. Analysis of the syntenic regions from several fishes strongly suggests that the smelt acquired the AFP gene from the herring.
[Mh] Termos MeSH primário: Proteínas Anticongelantes Tipo II/genética
Proteínas de Peixes/genética
Transferência Genética Horizontal
Osmeriformes/genética
[Mh] Termos MeSH secundário: Animais
Sequência de Bases
Cromossomos Artificiais Bacterianos
Evolução Molecular
Etiquetas de Sequências Expressas
Lectinas Tipo C/genética
Anotação de Sequência Molecular
Dados de Sequência Molecular
Filogenia
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Antifreeze Proteins, Type II); 0 (Fish Proteins); 0 (Lectins, C-Type)
[Em] Mês de entrada:1303
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:120927
[St] Status:MEDLINE
[do] DOI:10.1186/1471-2148-12-190


  3 / 18 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:21734021
[Au] Autor:Hall JR; Clow KA; Rise ML; Driedzic WR
[Ad] Endereço:Ocean Sciences Centre, Memorial Univ. of Newfoundland, 1 Marine Lab Road, St. John's, NL, A1C 5S7, Canada. jrhall@mun.ca
[Ti] Título:Identification and validation of differentially expressed transcripts in a hepatocyte model of cold-induced glycerol production in rainbow smelt (Osmerus mordax).
[So] Source:Am J Physiol Regul Integr Comp Physiol;301(4):R995-R1010, 2011 Oct.
[Is] ISSN:1522-1490
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Rainbow smelt (Osmerus mordax) avoid freezing by producing antifreeze protein (AFP) and accumulating glycerol. Glyceroneogenesis occurs in liver via a branch in glycolysis and gluconeogenesis and is activated by low temperature. Hepatocytes were isolated from the livers of fish acclimated to 8°C. Cells were incubated at warm (8°C; nonglycerol accumulating) or cold (0.4°C; glycerol accumulating) temperature over a 72-h time course. Reciprocal suppression subtractive hybridization libraries enriched for cold-responsive transcripts were constructed at 72 h. Microarray analyses using a 16K salmonid cDNA array were performed at 24, 48, and 72 h. Expression of type II AFP and 21 carbohydrate, amino acid, or lipid metabolism-related transcripts were validated using quantitative RT-PCR. Type II AFP transcript levels were not directly temperature related. In cold cells, levels of the glucose synthesis transcript were transiently higher. Increased glycerol production was not associated with increased phosphofructokinase or cytosolic glycerol-3-phosphate dehydrogenase transcript levels. Levels of transcripts (phosphoenolpyruvate carboxykinase, mitochondrial malate dehydrogenase, alanine aminotransferase, glutamate dehydrogenase, and aquaglyceroporin 9) associated with mobilization of amino acids to fuel glycerol accumulation were all transiently higher, suggesting a common regulatory mechanism. In cold compared with warm cells, pyruvate dehydrogenase kinase [an inhibitor of pyruvate dehydrogenase (PDH)] transcript levels were 20-fold higher. Potent inhibition of PDH would direct pyruvate and oxaloacetate derived from amino acids to glycerol, as opposed to oxidation via the citric acid cycle. Levels of a transcript potentially encoding glycerol-3-phosphatase, an enzyme not yet characterized in any vertebrate species, were higher following cold incubation. Finally, this study also presents the novel finding of increased glutamine synthetase transcript levels in response to low temperature.
[Mh] Termos MeSH primário: Temperatura Baixa
Glicerol/metabolismo
Hepatócitos/metabolismo
Osmeriformes/genética
Osmeriformes/fisiologia
Transcriptoma/genética
Transcriptoma/fisiologia
[Mh] Termos MeSH secundário: Aminoácidos/metabolismo
Animais
Proteínas Anticongelantes Tipo II/metabolismo
Metabolismo dos Carboidratos/fisiologia
Células Cultivadas
Perfilação da Expressão Gênica
Glutamato-Amônia Ligase/metabolismo
Hepatócitos/citologia
Masculino
Modelos Animais
Análise de Sequência com Séries de Oligonucleotídeos
Proteínas Serina-Treonina Quinases/metabolismo
Reprodutibilidade dos Testes
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amino Acids); 0 (Antifreeze Proteins, Type II); EC 2.7.11.1 (Protein-Serine-Threonine Kinases); EC 2.7.11.2 (pyruvate dehydrogenase (acetyl-transferring) kinase); EC 6.3.1.2 (Glutamate-Ammonia Ligase); PDC6A3C0OX (Glycerol)
[Em] Mês de entrada:1112
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:110708
[St] Status:MEDLINE
[do] DOI:10.1152/ajpregu.00210.2011


  4 / 18 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:18674542
[Au] Autor:Nishimiya Y; Kondo H; Takamichi M; Sugimoto H; Suzuki M; Miura A; Tsuda S
[Ad] Endereço:Functional Protein Research Group, Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology, 2-17-2-1 Tsukisamu-Higashi, Toyohira, Sapporo 062-8517, Japan.
[Ti] Título:Crystal structure and mutational analysis of Ca2+-independent type II antifreeze protein from longsnout poacher, Brachyopsis rostratus.
[So] Source:J Mol Biol;382(3):734-46, 2008 Oct 10.
[Is] ISSN:1089-8638
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We recently found that longsnout poacher (Brachyosis rostratus) produces a Ca(2+)-independent type II antifreeze protein (lpAFP) and succeeded in expressing recombinant lpAFP using Phichia pastoris. Here, we report, for the first time, the X-ray crystal structure of lpAFP at 1.34 A resolution. The lpAFP structure displayed a relatively planar surface, which encompasses two loop regions (Cys86-Lys89 and Asn91-Cys97) and a short beta-strand (Trp109-Leu112) with three unstructured segments (Gly57-Ile58, Ala103-Ala104, and Pro113-His118). Electrostatic calculation of the protein surface showed that the relatively planar surface was divided roughly into a hydrophobic area (composed of the three unstructured segments lacking secondary structure) and a hydrophilic area (composed of the loops and beta-strand). Site-directed mutation of Ile58 with Phe at the center of the hydrophobic area decreased activity significantly, whereas mutation of Leu112 with Phe at an intermediate area between the hydrophobic and hydrophilic areas retained complete activity. In the hydrophilic area, a peptide-swap mutant in the loops retained 60% activity despite simultaneous mutations of eight residues. We conclude that the epicenter of the ice-binding site of lpAFP is the hydrophobic region, which is centered by Ile58, in the relatively planar surface. We built an ice-binding model for lpAFP on the basis of a lattice match of ice and constrained water oxygen atoms surrounding the hydrophobic area in the lpAFP structure. The model in which lpAFP has been docked to a secondary prism (2-1-10) plane, which is different from the one determined for Ca(2+)-independent type II AFP from sea raven (11-21), appears to explain the results of the mutagenesis analysis.
[Mh] Termos MeSH primário: Proteínas Anticongelantes Tipo II/química
Proteínas Anticongelantes Tipo II/genética
Cálcio/metabolismo
Estrutura Terciária de Proteína
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Proteínas Anticongelantes Tipo II/metabolismo
Cristalografia por Raios X
Análise Mutacional de DNA
Gelo
Modelos Moleculares
Dados de Sequência Molecular
Mutagênese Sítio-Dirigida
Perciformes
Dobramento de Proteína
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Propriedades de Superfície
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Antifreeze Proteins, Type II); 0 (Ice); 0 (Recombinant Proteins); SY7Q814VUP (Calcium)
[Em] Mês de entrada:0809
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:080805
[St] Status:MEDLINE
[do] DOI:10.1016/j.jmb.2008.07.042


  5 / 18 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
[PMID]:17579720
[Au] Autor:Liu Y; Li Z; Lin Q; Kosinski J; Seetharaman J; Bujnicki JM; Sivaraman J; Hew CL
[Ad] Endereço:Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
[Ti] Título:Structure and evolutionary origin of Ca(2+)-dependent herring type II antifreeze protein.
[So] Source:PLoS One;2(6):e548, 2007 Jun 20.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In order to survive under extremely cold environments, many organisms produce antifreeze proteins (AFPs). AFPs inhibit the growth of ice crystals and protect organisms from freezing damage. Fish AFPs can be classified into five distinct types based on their structures. Here we report the structure of herring AFP (hAFP), a Ca(2+)-dependent fish type II AFP. It exhibits a fold similar to the C-type (Ca(2+)-dependent) lectins with unique ice-binding features. The 1.7 A crystal structure of hAFP with bound Ca(2+) and site-directed mutagenesis reveal an ice-binding site consisting of Thr96, Thr98 and Ca(2+)-coordinating residues Asp94 and Glu99, which initiate hAFP adsorption onto the [10-10] prism plane of the ice lattice. The hAFP-ice interaction is further strengthened by the bound Ca(2+) through the coordination with a water molecule of the ice lattice. This Ca(2+)-coordinated ice-binding mechanism is distinct from previously proposed mechanisms for other AFPs. However, phylogenetic analysis suggests that all type II AFPs evolved from the common ancestor and developed different ice-binding modes. We clarify the evolutionary relationship of type II AFPs to sugar-binding lectins.
[Mh] Termos MeSH primário: Proteínas Anticongelantes Tipo II/química
Proteínas Anticongelantes Tipo II/metabolismo
Cálcio/metabolismo
Evolução Molecular
Peixes/genética
[Mh] Termos MeSH secundário: Animais
Proteínas Anticongelantes Tipo II/genética
Sítios de Ligação
Cristalização
Cristalografia por Raios X
Peixes/metabolismo
Lectinas/metabolismo
Modelos Moleculares
Filogenia
Ligação Proteica
Conformação Proteica
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Antifreeze Proteins, Type II); 0 (Lectins); SY7Q814VUP (Calcium)
[Em] Mês de entrada:1004
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:070621
[St] Status:MEDLINE


  6 / 18 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
[PMID]:16754975
[Au] Autor:Nishimiya Y; Kondo H; Yasui M; Sugimoto H; Noro N; Sato R; Suzuki M; Miura A; Tsuda S
[Ad] Endereço:Functional Protein Research Group, Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira, Sapporo 062-8517, Japan.
[Ti] Título:Crystallization and preliminary X-ray crystallographic analysis of Ca2+-independent and Ca2+-dependent species of the type II antifreeze protein.
[So] Source:Acta Crystallogr Sect F Struct Biol Cryst Commun;62(Pt 6):538-41, 2006 Jun 01.
[Is] ISSN:1744-3091
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Ca2+-independent and Ca2+-dependent species of the type II antifreeze protein (AFP) were both crystallized using the hanging-drop vapour-diffusion method. It appeared that the crystal of the Ca2+-independent species from Brachyosis rostratus belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 43.3, b = 48.4, c = 59.7 A, and diffraction data were collected to 1.34 A resolution. For the Ca2+-dependent type II AFP species from Hypomesus nipponensis, crystallization was carried out for its Ca2+-free and Ca2+-bound states. 1.25 A resolution data were collected from the crystal in the Ca(2+)-free state, which exhibited P3(1)21 (or P3(2)21) symmetry, with unit-cell parameters a = b = 66.0, c = 50.3 A. Data collection could be extended to 1.06 A resolution for the crystal in the Ca2+ -bound state, which appeared to be isomorphous to the crystal in the Ca2+-free state (unit-cell parameters a = b = 66.0, c = 49.8 A). These data will allow us to determine the high-resolution structures of the two species of type II AFP.
[Mh] Termos MeSH primário: Proteínas Anticongelantes Tipo II/química
Cálcio/química
[Mh] Termos MeSH secundário: Animais
Cristalização
Cristalografia por Raios X
Osmeriformes
Solventes
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Antifreeze Proteins, Type II); 0 (Solvents); SY7Q814VUP (Calcium)
[Em] Mês de entrada:0608
[Cu] Atualização por classe:170219
[Lr] Data última revisão:
170219
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:060607
[St] Status:MEDLINE


  7 / 18 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:16330225
[Au] Autor:Scotter AJ; Kuntz DA; Saul M; Graham LA; Davies PL; Rose DR
[Ad] Endereço:Department of Biochemistry and the Protein Engineering Network Centres of Excellence, Queen's University, Kingston, Ont., Canada. scottera@post.queensu.ca
[Ti] Título:Expression and purification of sea raven type II antifreeze protein from Drosophila melanogaster S2 cells.
[So] Source:Protein Expr Purif;47(2):374-83, 2006 Jun.
[Is] ISSN:1046-5928
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We present a system for the expression and purification of recombinant sea raven type II antifreeze protein, a cysteine-rich, C-type lectin-like globular protein that has proved to be a difficult target for recombinant expression and purification. The cDNAs encoding the pro- and mature forms of the sea raven protein were cloned into a modified pMT Drosophila expression vector. These constructs produced N-terminally His(6)-tagged pro- and mature forms of the type II antifreeze protein under the control of a metallothionein promoter when transfected into Drosophila melanogaster S2 cells. Upon induction of stable cell lines the two proteins were expressed at high levels and secreted into the medium. The proteins were then purified from the cell medium in a simple and rapid protocol using immobilized metal affinity chromatography and specific protease cleavage by tobacco etch virus protease. The proteins demonstrated antifreeze activity indistinguishable from that of wild-type sea raven antifreeze protein purified from serum as illustrated by ice affinity purification, ice crystal morphology, and their ability to inhibit ice crystal growth. This expression and purification system gave yields of 95 mg/L of fully active mature sea raven type II AFP and 9.6 mg/L of the proprotein. This surpasses all previous attempts to express this protein in Escherichia coli, baculovirus-infected fall armyworm cells and Pichia pastoris and will provide sufficient protein for structural analysis.
[Mh] Termos MeSH primário: Proteínas Anticongelantes Tipo II/biossíntese
Proteínas Anticongelantes Tipo II/isolamento & purificação
Precursores de Proteínas/biossíntese
Precursores de Proteínas/isolamento & purificação
Proteínas Recombinantes/biossíntese
Proteínas Recombinantes/isolamento & purificação
[Mh] Termos MeSH secundário: Animais
Linhagem Celular
Cromatografia de Afinidade
Drosophila melanogaster
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Antifreeze Proteins, Type II); 0 (Protein Precursors); 0 (Recombinant Proteins); 0 (antifreeze protein, sea raven)
[Em] Mês de entrada:0609
[Cu] Atualização por classe:061115
[Lr] Data última revisão:
061115
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:051207
[St] Status:MEDLINE


  8 / 18 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:15544325
[Au] Autor:Li Z; Lin Q; Yang DS; Ewart KV; Hew CL
[Ad] Endereço:Division of Structural Biology, Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology and of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
[Ti] Título:The role of Ca2+-coordinating residues of herring antifreeze protein in antifreeze activity.
[So] Source:Biochemistry;43(46):14547-54, 2004 Nov 23.
[Is] ISSN:0006-2960
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The type II antifreeze protein of Atlantic herring (Clupea harengus harengus) requires Ca(2+) as a cofactor to inhibit the growth of ice crystals. On the basis of homology modeling with Ca(2+)-dependent lectin domains, five residues of herring antifreeze protein (hAFP) are predicted to be involved in Ca(2+) binding: Q92, D94, E99, N113, and D114. The role of E99, however, is less certain. A previous study on a double mutant EPN of hAFP suggested that the Ca(2+)-binding site of hAFP was the ice-binding site. However, it is possible that Ca(2+) might function distantly to affect ice binding. Site-directed mutagenesis was performed on the Ca(2+)-coordinating residues of hAFP in order to define the location of the ice-binding site and to explore the role of these residues in antifreeze activity. Properties of the mutants were investigated in terms of their structural integrity and antifreeze activity. Equilibrium dialysis analysis demonstrated that E99 is a Ca(2+)-coordinating residue. Moreover, proteolysis protection assay revealed that removal of Ca(2+) affected the conformation of the Ca(2+)-binding loop rather than the core structure of hAFP. This finding rules out the possibility that Ca(2+) might act at a distance via a conformational change to affect the function of hAFP. Substitutions at positions 99 and 114 resulted in severely reduced thermal hysteresis activity. These data indicate that the ice-binding site of hAFP is located at the Ca(2+)-binding site and the loop region defined by residues 99 and 114 is important for antifreeze activity.
[Mh] Termos MeSH primário: Aminoácidos/química
Proteínas Anticongelantes Tipo II/química
Cálcio/química
Gelo
[Mh] Termos MeSH secundário: Alanina/genética
Amidas
Aminoácidos/genética
Animais
Proteínas Anticongelantes Tipo II/genética
Cloreto de Cálcio/química
Radioisótopos de Cálcio/metabolismo
Proteínas de Ligação ao Cálcio/química
Proteínas de Ligação ao Cálcio/genética
Cristalização
Medição da Troca de Deutério
Hidrólise
Mutagênese Sítio-Dirigida
Conformação Proteica
Serina Endopeptidases/química
Espectrometria de Fluorescência
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amides); 0 (Amino Acids); 0 (Antifreeze Proteins, Type II); 0 (Calcium Radioisotopes); 0 (Calcium-Binding Proteins); 0 (Ice); EC 3.4.21.- (Serine Endopeptidases); EC 3.4.21.19 (glutamyl endopeptidase); M4I0D6VV5M (Calcium Chloride); OF5P57N2ZX (Alanine); SY7Q814VUP (Calcium)
[Em] Mês de entrada:0501
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:041117
[St] Status:MEDLINE


  9 / 18 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:14705940
[Au] Autor:Marshall CB; Tomczak MM; Gauthier SY; Kuiper MJ; Lankin C; Walker VK; Davies PL
[Ad] Endereço:Departments of Biochemistry and Biology, Queen's University, Kingston, Ontario K7L 3N6, Canada.
[Ti] Título:Partitioning of fish and insect antifreeze proteins into ice suggests they bind with comparable affinity.
[So] Source:Biochemistry;43(1):148-54, 2004 Jan 13.
[Is] ISSN:0006-2960
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Antifreeze proteins (AFPs) inhibit the growth of ice by binding to the surface of ice crystals, preventing the addition of water molecules to cause a local depression of the freezing point. AFPs from insects are much more effective at depressing the freezing point than fish AFPs. Here, we have investigated the possibility that insect AFPs bind more avidly to ice than fish AFPs. Because it is not possible to directly measure the affinity of an AFP for ice, we have assessed binding indirectly by examining the partitioning of proteins into a slowly growing ice hemisphere. AFP molecules adsorbed to the surface and became incorporated into the ice as they were overgrown. Solutes, including non-AFPs, were very efficiently excluded from ice, whereas AFPs became incorporated into ice at a concentration roughly equal to that of the original solution, and this was independent of the AFP concentration in the range (submillimolar) tested. Despite their >10-fold difference in antifreeze activity, fish and insect AFPs partitioned into ice to a similar degree, suggesting that insect AFPs do not bind to ice with appreciably higher affinity. Additionally, we have demonstrated that steric mutations on the ice binding surface that decrease the antifreeze activity of an AFP also reduce its inclusion into ice, supporting the validity of using partitioning measurements to assess a protein's affinity for ice.
[Mh] Termos MeSH primário: Proteínas Anticongelantes Tipo II/química
Proteínas Anticongelantes Tipo II/metabolismo
Proteínas Anticongelantes/química
Proteínas Anticongelantes/metabolismo
Congelamento
[Mh] Termos MeSH secundário: Animais
Proteínas Anticongelantes/genética
Proteínas Anticongelantes Tipo II/genética
Peixes
Mariposas
Mutagênese Sítio-Dirigida
Mioglobina/química
Perciformes
Ligação Proteica/genética
Soluções
Tenebrio
Fatores de Tempo
alfa-Fetoproteínas/química
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Antifreeze Proteins); 0 (Antifreeze Proteins, Type II); 0 (Myoglobin); 0 (Solutions); 0 (alpha-Fetoproteins); 0 (antifreeze protein, sea raven)
[Em] Mês de entrada:0405
[Cu] Atualização por classe:061115
[Lr] Data última revisão:
061115
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:040107
[St] Status:MEDLINE


  10 / 18 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
[PMID]:14628471
[Au] Autor:Peng SH; Yao PC; Xu NY
[Ti] Título:[Characteristics and mechanism of the antifreeze protein].
[So] Source:Sheng Li Ke Xue Jin Zhan;34(3):238-40, 2003 Jul.
[Is] ISSN:0559-7765
[Cp] País de publicação:China
[La] Idioma:chi
[Mh] Termos MeSH primário: Proteínas Anticongelantes Tipo II/fisiologia
Proteínas Anticongelantes/fisiologia
[Mh] Termos MeSH secundário: Animais
Proteínas Anticongelantes/biossíntese
Proteínas Anticongelantes/genética
Proteínas Anticongelantes Tipo II/biossíntese
Proteínas Anticongelantes Tipo II/genética
Sítios de Ligação
Glicoproteínas/fisiologia
Seres Humanos
Gelo
Ligação Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Antifreeze Proteins); 0 (Antifreeze Proteins, Type II); 0 (Glycoproteins); 0 (Ice)
[Em] Mês de entrada:0407
[Cu] Atualização por classe:081121
[Lr] Data última revisão:
081121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:031125
[St] Status:MEDLINE



página 1 de 2 ir para página        
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde