Glycation of biomolecules leads to the formation of advanced glycation end products (AGEs). Glycation of immunoglobulin G (IgG) has been implicated in autoimmune diseases such as rheumatoid arthritis (RA). In this study, human IgG was glycated with physiological concentration of glucose. The changes induced in IgG were analyzed by UV, fluorescence, circular dichroism, and Fourier transform infrared (FTIR) spectroscopy; thermal denaturation studies, native, and Sodium dodecyl sulphate (SDS)‐polyacrylamide gel electrophoresis. The ketoamine moieties and carbonyl content were also quantitated in glycated IgG. We report structural perturbations, increased carbonyl content, and ketoamine moieties in the glycated IgG. This may interfere with the normal function of IgG and may contribute to initiation of arthritic complications. AGEs damaged IgG may be used as a biomarker for early detection of RA and the associated secondary complications. © 2012 IUBMB Life, 2012

At pH 2, ovalbumin retains native-like secondary structure as seen by far-UV CD and FTIR, but lacks well-defined tertiary structure as seen by the fluorescence and near-UV CD spectra. Addition of 20 mM Trifluoroacetic acid (TFA) or 30 mM Trichloroacetic acid (TCA) on acid-induced state results in protein aggregation. This aggregated state possesses extensive β-sheet structure as revealed by far-UV CD and FTIR spectroscopy. Furthermore, the aggregates exhibit decreased ANS fluorescence and increased thioflavin T fluorescence. The presence of aggregates was confirmed by size exclusion chromatography. Such a formation of β-sheet structure is found in the amyloid of a number of neurological diseases such as Alzheimer's and scrapie. Ovalbumin at low pH, in the presence of K(2)SO(4), exists in partially folded state characterized by native-like secondary structure and tertiary folds.

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It has been shown that vibration level, push force, exposure duration and working posture cause unfavorable effects on the work performance when hand held vibrating tools are used by operators. The present study analyzed the effects of these variables on the heart rate and systolic blood pressure of the operators carrying out a manual-grinding task. Four levels of vibration (12.5, 13.6, 14.8 and 18 m/s2), three levels of push force (5, 10, 15 N), three levels of working posture (180°, 150° and 120° elbow flexion) and three exposure durations of 3, 5 and 7 min were selected for the study. Thirty male subjects with no prior experience in the field of grinding participated in the study. Results indicated that in the kind of task undertaken, the main effect of equivalent level of vibration, exposure duration, push force and working posture were all statistically significant. Also an increase in the change in blood pressure and heart rate values were observed with the increase in exposure duration and push force. When the task was performed with flexion angle of 120°, change in heart rate and blood pressure values was minimum when compared with the other two working postures. Relevance to industry: Workers using various hand held tools are prone to injuries. Present research may help greatly in reducing task related injuries and enhance performance.