Further characterization of the subunits of the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) by SDS-PAGE electrophoresis and MALDI-TOF-MS

Further characterization of hemoglobin of Glossoscolex paulistus (HbGp) subunits was performed based on SDS-PAGE, size exclusion chromatography (SEC) and MALDI-TOF-MS analysis. SDS-PAGE has shown a total of four linker chains, two quite intense and two of lower intensity. HbGp fractions (I-VI), obtained by size exclusion chromatography (SEC), from oligomeric dissociation at alkaline pH 9.6, were monitored. Fraction I is identical to the whole protein. The monomeric chains c, obtained from the trimer abc reduction, present four isoforms with MM 17,336 Da, 17,414 Da, 17,546 Da and 17,620 Da. Furthermore, the trimer subunit presents two isoforms, T 1 and T 2, with MM 51,200 ± 60 and 51,985 ± 50 Da, respectively. Based on SDS-PAGE, the linker chains seem to be distributed along the different fractions of the SEC chromatogram, appearing along the peaks corresponding to fractions I-V. The fraction IV contains, predominantly, trimers with some linkers contamination. The strong interaction of linker chains L with the trimers abc, makes it difficult to obtain these subunits in pure form. The monomer d in fraction VI appears to be quite pure, in agreement with previous studies. © 2011 Elsevier Ltd. All rights reserved.

The acylpolyamines from spider venoms

Acylpolyamines are low molecular mass toxins occurring exclusively in the venoms from solitary wasps and some groups of spiders. Their chemical structures have been elucidated using hyphenated techniques of mass spectrometry, such as LC-MS and MS/MS, or through direct analysis with different types of NMR analyses. The chemical structures of the acylpolyamine toxins from the venoms of Nephilinae orb-web spiders appear to be organized into four parts based on the combinatorial way that the chemical building blocks are bound to each other. An aromatic moiety (part I) is connected through a linker amino acid (part II) to a polyamine chain (part III), which in turn may be connected to an optional tail (part IV). The polyamine chains were classified into seven subtypes according to the different combinations of chemical building blocks. These polyamine chains, in turn, are connected to one of three chromophore moieties: a 2,4-dihydroxyphenyl acetyl group, a 4-hydroxyindolyl acetyl group, or an indolyl acetyl group. They may be connected through an asparagine residue or sometimes through the dipeptide ornithyl asparagine. Also, nine different types of backbone tails may be attached to the polyamine chains. These toxins are noncompetitive blockers of ionotropic glutamate receptors with neuroprotective action against the neuronal death and antiepileptic effect. Thus, compounds of this class of spider venom toxin seem to represent interesting molecular models for the development of novel neuropharmaceutical drugs. © 2012 Elsevier B.V. All rights reserved.

Small-angle X-ray scattering and structural modeling of full-length: Cellobiohydrolase I from Trichoderma harzianum

Cellobiohydrolases hydrolyze cellulose releasing cellobiose units. They are very important for a number of biotechnological applications, such as, for example, production of cellulosic ethanol and cotton fiber processing. The Trichoderma cellobiohydrolase I (CBH1 or Cel7A) is an industrially important exocellulase. It exhibits a typical two domain architecture, with a small C-terminal cellulose-binding domain and a large N-terminal catalytic core domain, connected by an O-glycosylated linker peptide. The mechanism by which the linker mediates the concerted action of the two domains remains a conundrum. Here, we probe the protein shape and domain organization of the CBH1 of Trichoderma harzianum (ThCel7A) by small angle X-ray scattering (SAXS) and structural modeling. Our SAXS data shows that ThCel7A linker is partially-extended in solution. Structural modeling suggests that this linker conformation is stabilized by inter- and intra-molecular interactions involving the linker peptide and its O-glycosylations. © 2013 Springer Science+Business Media Dordrecht.

Influência da carga da extremidade amino-terminal da esticolisina II: atividade biológica e interação com miméticos de membrana

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da resistência em caprinos a ninfas do carrapato Amblyomma cajennense (Fabricius, 1787) e da reatividade cruzada com A. hebraeum (Koch, 1844) (Acari:Ixodidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Produção dos fragmentos de anticorpos recombinantes scFv-N e scFv-S1 e suas aplicações na detecção e diferenciação do Vírus da Bronquite Infecciosa

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Clonagem e expressão de fragmentos de anticorpos (scFV) contra o vírus da leucemia felina (FeLV) por phage display

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Citotoxicidade transdentinária e efeito da carbodiimida (EDC) na biomodificação do colágeno dentinário e na degradação da interface adesiva

Pós-graduação em Ciências Odontológicas - FOAR

Simulação computacional e síntese de polímero molecularmente impresso para extração em fase sólida (MISPE) de ciprofloxacina em urina

Pós-graduação em Química - IQ

Modular Hyperthermostable Bacterial Endo-beta-1, 4-Mannanase: Molecular Shape, Flexibility and Temperature-Dependent Conformational Changes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural and functional characterization of the chaperone Hsp70 from sugarcane. Insights into conformational changes during cycling from cross-linking/mass spectrometry assays

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aspergillus niger beta-Glucosidase Has a Cellulase-like Tadpole Molecular Shape INSIGHTS INTO GLYCOSIDE HYDROLASE FAMILY 3 (GH3) beta-GLUCOSIDASE STRUCTURE AND FUNCTION

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Deconstructing the DGAT1 enzyme: Binding sites and substrate interactions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Obtention and characterization of collagen and chitosan based cements for bone regerneration. Part 1: extraction and characterization of collagen

Several cements are used as biomaterials. Biopolymers such as chitosan and collagen exhibit excellent biocompatibility and can be used in the remodeling of bone tissue. The cement must have high mechanical strength and compatibility with original tissue. In this context, the objective of this study was to extract, characterize and cross-link collagen from bovine tendon, forlater associate it with chitosan and calcium phosphate to obtain cements for bone regeneration. Glutaraldehyde was used as cross-linker in 0.1, 0.5, 1.0 and 10% concentration. Infrared analysis confirmed the presence of functional groups characteristic of collagen, whereas the capacity of water absorption decreased with the increasing of cross-linking degree. Denaturation temperatures of collagen samples were obtained by Differential Scanning Calorimetry and Scanning Electron Microscopy showed the fiber structure characteristics of collagen, which were more organized for high degree of cross-linking samples.

Efeitos da dimerização na estrutura e atividade biológica dos peptídeos antimicrobianos Aureína 1.2 e Magainina 2

Pós-graduação em Biotecnologia - IQ