Novel chiroptical analysis of hemoglobin by surface enhanced resonance Raman optical activity spectroscopy

Abstract

The metalloprotein hemoglobin (Hb) was studied using surface enhanced resonance Raman spectroscopy (SERRS) and surface enhanced resonance Raman optical activity (SERROA). The SERROA results are analyzed and compared with the SERRS, and the later to the resonance Raman (RRS) performed on Hb. The SERRS measurements careful optimization, with respect to the concentration and volume ratio of the analyte to colloids, enables for the first time SERROA of this molecule. We observed that the most intense SERROA signals were attributed the m 4 , m 20 , and m 21 vibrations, which are sensitive to the redox state of the heme's iron ion, and to the presence of its sixth site, bound to exogenous ligand; O 2 , NO or CO. However, in this study, the SERROA signals corresponding to these vibrations appear more sensitive to the Hb oxygen-binding properties than they appear in the SERRS or RRS. Moreover, the SER-ROA signal of Hb has successfully been monitored as a function of time, and was observed to be stable for 4-5 min. To our knowledge, the SERROA results of Hb, and its comparison to SERRS and RRS, are here reported for the first time.

Replacing Heme with Paclitaxel to Prepare Drug-Loaded Globin Nanoassembles for CD163 Targeting

“…To prepare samples for surface‐enhanced Raman spectroscopy (SERS), silver colloid was prepared first, then Gb‐NPs‐PTX and globin solutions with 10 −7 –10 −8 M protein concentration were dropped on precooling sliver colloid films, and were air dried naturally at room temperature. SERS spectra were obtained by using a JY Labram HR 800 Raman microscope (Paris, French), with 488 nm excitation laser .…”

Surface-enhanced resonance Raman scattering of hemoproteins and those in complicated biological systems

“…By excitation at 532 nm, the SE(R)RS was measured mainly using colloidal AgNPs. [82][83][84][85][86][87] For example, the SE(R)RS has been used for sensitive discrimination between Hb and glycated Hb. 87 It is noted that the SE(R)RS with 532 nm excitation was combined with matrix-assisted laser desorption/ionization mass spectroscopy (MALDI-MS).…”

Use of a hydrogel polymer for reproducible surface enhanced Raman optical activity (SEROA)

“…However, the generation of reliable SEROA spectra of biomolecules has been problematic due to difficulties in controlling spectral artefacts and low signal-to-noise ratios which complicate detection of true SEROA signals. Although several papers have presented possible SEROA spectra, 11,12 currently a proof demonstrating mirror image SEROA spectra from opposite enantiomers has not been reported. Recently, observation of SEROA spectra for the L-and D-enantiomers of cysteine has been claimed; 13 however the authors stated that no corresponding SERS spectra could be measured under the same conditions.…”