Diseño de un sistema de indicadores socio ambientales para el Distrito Capital de Bogotá

El presente documento contiene un resumen del "Proyecto de Diseño de un Sistema de Indicadores Socio-Ambientales para el Distrito Capital de Bogotá". En él se exponen los distintos elementos previstos como componentes del proyecto, en la siguiente forma: después de una breve exposición de los antecedentes, se presenta un marco conceptual que brinda los elementos básicos para la comprensión del tema central del trabajo como es la relación entre los procesos sociales y los procesos ambientales; luego, se presenta el contexto institucional y urbano al que se refiere el sistema propuesto; a continuación se incluye el marco metodológico que reviste especial importancia por cuanto permite la articulación del PLAN MAESTRO DE GESTION AMBIENTAL - PMGA- con el sistema de indicadores y, finalmente, se expone el sistema y se presentan las principales variables e indicadores que hacen parte del mismo. La metodología del proyecto hace explícita la forma de relacionamiento de las variables sociales y ambientales; esta es desarrollada en los indicadores presentados en el modelo Presión-Estado- Respuesta, que es el mismo que utiliza el PMGA.

Proteolytic enzyme-immobilization techniques for MS-based protein analysis

Protein digestion utilizing proteases (e.g., trypsin, Lys C and other proteolytic enzymes) is one of the key sample-preparation steps in contemporary proteomics, followed by liquid chromatography coupled to mass spectrometry (MS). Tryptic digestion is traditionally performed in aqueous solutions, usually applying the enzyme and the sample in a 50:1 protein-to-protease ratio. Long digestion times (up to 24 h), auto-digestion sub-products and poor enzyme-to-substrate ratio are common issues with liquid-phase protein-digestion processes. The use of enzymes immobilized onto solid supports can minimize these problems by increasing enzyme-to-substrate ratios, significantly speeding up digestion times and reducing autolysis. The other main goal of protease immobilization is to obtain rugged, efficient enzyme reactors. In this article, we review the most important proteolytic enzyme-immobilization techniques with the main emphasis on fabrication of trypsin microreactors and nanoreactors and their utilization in bottom-up proteomics. We also discuss data reportedly obtained using the various immobilization protocols with respect to enzyme activity and MS-sequence coverage

Fractionation of the human plasma proteome for monoclonal antibody proteomics-based biomarker discovery

mAb proteomics, a reversed biomarker discovery approach, is a novel methodology torecognize the proteins of biomarker potential, but requires subsequent antigen identificationsteps. While in case of high-abundant proteins, it generally does not represent aproblem, for medium or lower abundant proteins, the identification step requires a largeamount of sample to assure the proper amount of antigen for the ID process. In thisarticle, we report on the use of combined chromatographic and precipitation techniquesto generate a large set of fractions representing the human plasma proteome, referred toas the Analyte Library, with the goal to use the relevant library fractions for antigenidentification in conjunction with mAb proteomics. Starting from 500 mL normal pooledhuman plasma, this process resulted in 783 fractions with the average protein concentrationof 1 mg/mL. First, the serum albumin and immunoglobulins were depletedfollowed by prefractionation by ammonium sulfate precipitation steps. Each precipitatewas then separated by size exclusion chromatography, followed by cation and anionexchange chromatography. The 20 most concentrated ion exchange chromatographyfractions were further separated by hydrophobic interaction chromatography. All chromatographyand precipitation steps were carefully designed aiming to maintain thenative forms of the intact proteins throughout the fractionation process. The separationroute of vitamin D-binding protein (an antibody proteomics lead) was followed in allmajor fractionation levels by dot blot assay in order to identify the library fraction itaccumulated in and the identity of the antigen was verified by Western blot