Structure-function relationships of the peptide Paulistine: A novel toxin from the venom of the social wasp Polybia paulista

Background: The peptide Paulistine was isolated from the venom of wasp Polybia paulista. This peptide exists under a natural equilibrium between the forms: oxidised - with an intra-molecular disulphide bridge; and reduced - in which the thiol groups of the cysteine residues do not form the disulphide bridge. The biological activities of both forms of the peptide are unknown up to now. Methods: Both forms of Paulistine were synthesised and the thiol groups of the reduced form were protected with the acetamidemethyl group [Acm-Paulistine] to prevent re-oxidation. The structure/activity relationships of the two forms were investigated, taking into account the importance of the disulphide bridge. Results: Paulistine has a more compact structure, while Acm-Paulistine has a more expanded conformation. Bioassays reported that Paulistine caused hyperalgesia by interacting with the receptors of lipid mediators involved in the cyclooxygenase type II pathway, while Acm-Paullistine also caused hyperalgesia, but mediated by receptors involved in the participation of prostanoids in the cyclooxygenase type II pathway. Conclusion: The acetamidemethylation of the thiol groups of cysteine residues caused small structural changes, which in turn may have affected some physicochemical properties of the Paulistine. Thus, the dissociation of the hyperalgesy from the edematogenic effect when the actions of Paulistine and Acm-Paulistine are compared to each other may be resulting from the influence of the introduction of Acm-group in the structure of Paulistine. General significance: The peptides Paulistine and Acm-Paulistine may be used as interesting tools to investigate the mechanisms of pain and inflammation in future studies. © 2013 Elsevier B.V.

Documento conjunto de las comisiones regionales para la Primera Reunión del Comité Preparatorio de la Conferencia Mundial en la Cumbre sobre Desarrollo Social = Joint paper of the regional commissions for the First Meeting of the Preparatory Committee of the Whole of the World Summit for Social Development

Incluye Bibliografía

Procedimientos de la Consulta sobre el Desarrollo de las Industrias Forestales y de la Pulpa y Papel en América Latina = Proceedings of the Consultation on Development of the Forest and Pulp and Paper Industries in Latin America

Incluye Bibliografía

Report of the Latin American Meeting of Experts on the Pulp and Paper Industry

Includes Addendum: pulp and paper prospects in Latin America

Prospects for Latin American pulp and paper exports to overseas

Includes bibliography

Working Group on the Methodology for the Study of International Migration: introductory paper for the meeting

Se detallan los antecedentes del proceso de constitucion del grupo de trabajo sobre la metodologia para el estudio de la migracion internacional y se plantean algunas bases para la discusion en la primera reunion de dicho grupo a realizarse en Helsinki en septiembre de 1978. Se aportan datos sobre la labor desarrollada por el Centro Latinoamericano de Demografia (CELADE) en el estudio de las migraciones internacionales en los paises latinoamericanos. Se inserta la agenda de la reunion de Helsinki.

Estudio sobre interconexión eléctrica del Istmo Centroamericano: aplicación del modelo WASP-3 a los sistemas nacionales

Incluye Bibliografía

Estudio sobre interconexión eléctrica del Istmo Centroamericano: aplicación del modelo WASP al estudio

Incluye Bibliografía

Modificaciones introducidas al modelo WASP para su utilización en el proyecto regional de interconexión eléctrica del Istmo Centroamericano

Incluye Bibliografía

Commodity paper on coffee research policy and management in Trinidad and Tobago

Presenta los objetivos del programa de investigación nacional para mejorar la producción de la industria del café en Trinidad y Tabago.

Jamaica country paper

Includes bibliography

Haiti country paper

Includes bibliography

Dominica country paper

Includes bibliography