Identification and further characterization of antibody charge variants is a crucial step during biopharmaceutical drug development, particularly with regard to the increasing complexity of novel... Show moreIdentification and further characterization of antibody charge variants is a crucial step during biopharmaceutical drug development, particularly with regard to the increasing complexity of novel antibody formats. As a standard analytical approach, manual offline fractionation of charge variants by cation-exchange chromatography followed by comprehensive analytical testing is applied. These conventional workflows are time-consuming and labor-intensive and overall reach their limits in terms of chromatographic separation of enhanced structural heterogeneities raised from new antibody formats. For these reasons, we aimed to develop an alternative online characterization strategy for charge variant characterization of a therapeutic bispecific antibody by online mD-LC-MS at middle-up (2D-LC-MS) and bottom-up (4D-LC-MS) level. Using the implemented online mD-LC-MS approach, all medium-and even low-abundant product variants previously identified by offline fraction experiments and liquid chromatography mass spectrometry could be monitored. The herein reported automated online mD-LC-MS methodology therefore represents a complementary and in part alternative approach for analytical method validation including multiattribute monitoring (MAM) strategies by mass spectrometry, offering various benefits including increased throughput and reduced sample handling and combined protein information at intact protein and peptide level. Show less
Plant functional traits directly affect ecosystem functions. At the species level, trait combinations depend on trade-offs representing different ecological strategies, but at the community level... Show morePlant functional traits directly affect ecosystem functions. At the species level, trait combinations depend on trade-offs representing different ecological strategies, but at the community level trait combinations are expected to be decoupled from these trade-offs because different strategies can facilitate co-existence within communities. A key question is to what extent community-level trait composition is globally filtered and how well it is related to global versus local environmental drivers. Here, we perform a global, plot-level analysis of trait-environment relationships, using a database with more than 1.1 million vegetation plots and 26,632 plant species with trait information. Although we found a strong filtering of 17 functional traits, similar climate and soil conditions support communities differing greatly in mean trait values. The two main community trait axes that capture half of the global trait variation (plant stature and resource acquisitiveness) reflect the trade-offs at the species level but are weakly associated with climate and soil conditions at the global scale. Similarly, within-plot trait variation does not vary systematically with macro-environment. Our results indicate that, at fine spatial grain, macro-environmental drivers are much less important for functional trait composition than has been assumed from floristic analyses restricted to co-occurrence in large grid cells. Instead, trait combinations seem to be predominantly filtered by local-scale factors such as disturbance, fine-scale soil conditions, niche partitioning and biotic interactions. Show less
Bokma, J.P.; Winter, M.; Oosterhof, T.; Vliegen, H.; Dijk, A. van; Hazekamp, M.; ... ; Bouma, B. 2015
