Ultraviolet Absorption Spectroscopy of Peptides

Abstract

UV absorption spectroscopy is commonly used with peptides for determining concentration and enzyme activity, but high-resolution UV spectra can also provide information on peptide secondary and tertiary structure and association behavior. New developments using temperature- and cation-dependent high-resolution second derivative absorption methods can also provide information concerning peptide dynamics. Data from several low-resolution spectroscopic techniques, including UV absorption, can be combined to generate an overall picture of peptide structure as a function of environmental conditions.

Stability and structure–activity relationship of the SPA4 peptide under ambient and stressed conditions of lung injury

“…Although peaks of these aromatic amino acids may overlap, we divided the fourthderivative spectra (240-310 nm) into three regions for (240-270 nm) phenylalanine, (270-290 nm) tyrosine, and (290-310 nm) tryptophan amino acids for analyzing any changes in the peaks or vibrational ne structures. 29 UV-VIS spectra of the SPA4 peptide at different pH (range 3.0-10.0) and temperatures (range 25-37 °C)…”

“…Fourth-order derivative spectra (second derivative of second derivative) of original UV-VIS spectra were obtained and analyzed for area under the curve (AUC), number of peaks above the baseline, and vibrational ne structures related to phenylalanine (F), tyrosine (Y) and tryptophan (W) residues of SPA4 peptide under different conditions using GraphPad Prism soware, which utilizes the Savitzky and Golay's principle of differentiation of data. 28,29 Primary structure or stability of the SPA4 peptide over time and at different pH and temperatures. The stock solution of SPA4 peptide (834.2 mM) was kept at room temperature or at 4 °C for a period of 10 days, and an aliquot was subjected to UV-VIS spectroscopy at an interval of 24 h as described above.…”

Microcystin‐LR Detected in a Low Molecular Weight Fraction from a Crude Extract of Zoanthus sociatus

“…Unlike microcystins, the UV maximum absorbance for the first peak was 264 nm, whereas the second peak showed a UV maximum absorbance at 220–274 nm (Supplementary Figure S2), resembling a typical UV spectra of peptides [42,43,44,45]. In contrast to Liquid chromatography combining multi-stage mass spectrometry (MC-LC/MS), UV-based methods do not provide unequivocal identification of known, unexpected and/or trace levels of microcystins [46].…”

Anti‐CD30 (Ber‐H2) epitope requires structural elements as shown by mass spectroscopy and dual‐site associated kinetics

“…Purification of the sequences can improve MS results by providing a more targeted sample. Physical peptide separation is performed with chromatography [38][39][40] or gel electrophoresis. [41][42][43] Following the aforementioned roadmap, the to digest the recombinant protein, separate the constituents, and determine the missing sequence element by MS were and tested.…”