Enrichment and analysis of nonenzymatically glycated peptides: Boronate affinity chromatography coupled with electron-transfer dissociation mass spectrometry

Nonenzymatic glycation of peptides and proteins by D-glucose has important implications in the pathogenesis of diabetes mellitus, particularly in the development of diabetic complications. However, no effective high-throughput methods exist for identifying proteins containing this low-abundance posttranslational modification in bottom-up proteomic studies. In this report, phenylboronate affinity chromatography was used in a two-step enrichment scheme to selectively isolate first glycated proteins and then glycated, tryptic peptides from human serum glycated in vitro. Enriched peptides were subsequently analyzed by alternating electron-transfer dissociation (ETD) and collision induced dissociation ( CID) tandem mass spectrometry. ETD fragmentation mode permitted identification of a significantly higher number of glycated peptides (87.6% of all identified peptides) versus CID mode (17.0% of all identified peptides), when utilizing enrichment on first the protein and then the peptide level. This study illustrates that phenylboronate affinity chromatography coupled with LC-MS/MS and using ETD as the fragmentation mode is an efficient approach for analysis of glycated proteins and may have broad application in studies of diabetes mellitus.

The effect of feeder type and change of feeder type on growing and finishing pig performance and behaviour

Reduced feed intake and hence lower growth rates commonly occur when the environment of the pig changes, e.g. at weaning and when pigs are moved from growing accommodation to finishing accommodation. It is hypothesised that if environmental factors, such as feeder type, remain the same in the weaning and finishing accommodation this 'growth check' may be reduced. A total of 640 pigs in 32 pens of 20 pigs per pen were used to investigate the effects of two feeder types and changing or not changing the feeder type at 10 weeks of age on growth performance and behaviour in the periods from 4 to 10, 10 to finish (22) and from 4 to finish (22) weeks of age, respectively. The two feeder types tested were a 'wet and dry' single-space (S) feeder and a 'dry' multi-space feeder (M).

Influence of group size during the post-weaning period on the performance and behaviour of pigs

The aim of this study was to assess the effect of group size during the post-weaning period on the performance and behaviour of pigs. A total of 1280 pigs were allocated to one of five group sizes from weaning at 4 weeks of age until 10 weeks of age. The group sizes consisted of 10, 20, 30, 40 or 60 pigs, and groups were balanced for gender and weight. All pigs were housed at a constant space allowance and one 4-space dry feeder and drinker was provided per 10 animals. Group size did not significantly affect growth rate; however, the coefficient of variation for growth was greater in groups of 10 than in larger groups, and this reached significance (P

Influence of feeder type on the performance and behaviour of weaned pigs

In this study, 1124 week-old pigs were allocated at weaning in groups of 20 to one of five feeder types. These consisted of two multi-space designs ('dry' and 'wet and dry'), two feeders with communal troughs ('communal-rectangular' and 'communal-circular') and a single-space feeder. All feeders supplied water except the 'dry' multi-space feeder, Feed disappearance was higher and food conversion was poorer with 'wet and dry' multi-space feeders than with all other feeder types (P

Influence of environmental enrichment on the behaviour, performance and meat quality of domestic pigs

Three hundred and twenty pigs were reared from birth to slaughter at 21 weeks in either barren or enriched environments. The barren environments were defined as intensive housing (slatted floors and minimum recommended space allowances) and the enriched environments incorporated extra space, an area which contained peat and straw in a rack. Behavioural observations showed that environmental enrichment reduced time spent inactive and time spent involved in harmful social and aggressive behaviour while increasing the time spent in exploratory behaviour. During the finishing period (15-21 weeks) mean daily food intakes were higher and food conversion ratios were lower for pigs in enriched environments compared with their counterparts in barren environments (P