000131548 001__ 131548
000131548 005__ 20240319080948.0
000131548 0247_ $$2doi$$a10.1007/s00723-021-01428-w
000131548 0248_ $$2sideral$$a126070
000131548 037__ $$aART-2022-126070
000131548 041__ $$aeng
000131548 100__ $$aSerra, I
000131548 245__ $$aPitfalls in Sample Preparation of Metalloproteins for Low-Temperature EPR: The Example of Alkaline Myoglobin
000131548 260__ $$c2022
000131548 5060_ $$aAccess copy available to the general public$$fUnrestricted
000131548 5203_ $$aDue to fast relaxation processes of transition metal ions, electron paramagnetic resonance (EPR) spectroscopy of metalloproteins needs to be performed at cryogenic temperatures. To avoid damaging the biological system upon freezing, a cryoprotectant is generally added to the sample as a glassing agent. Even though cryoprotectants are expected to be inert substances, evidences in literature show their non-innocent role in altering the shape of EPR spectra of proteins and biological objects in general. In this work we conduct a systematic study on the impact of several experimental factors-such as buffer composition, choice of cryoprotectant, pH and temperature-on the EPR spectrum of myoglobin, taken as a reference system for being a well-characterized heme-containing protein. We focus on high-pH buffers to induce and investigate the alkaline transition of ferric myoglobin (pKa similar to 8.9). A combined approach of continuous-wave EPR and UV-visible absorption spectroscopy shows that using particular pairs of buffers and cryoprotectants determines a considerable pH variation in the sample and that this effect is enhanced at cryogenic temperature. In addition, phase memory times were measured to evaluate the efficiency of different cryoprotectants and compared with spectral linewidths in continuous-wave EPR. Our findings suggest that among the selected cryoprotectants ethylene glycol is rather effective, even more than the widely used glycerol, without having unwanted effects.
000131548 536__ $$9info:eu-repo/grantAgreement/EC/H2020/813209/EU/Paramagnetic Species in Catalysis Research. A Unified Approach Towards Heterogeneous, Homogeneous and Enzyme Catalysis/PARACAT$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 813209-PARACAT
000131548 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000131548 590__ $$a1.0$$b2022
000131548 591__ $$aSPECTROSCOPY$$b32 / 41 = 0.78$$c2022$$dQ4$$eT3
000131548 591__ $$aPHYSICS, ATOMIC, MOLECULAR & CHEMICAL$$b32 / 35 = 0.914$$c2022$$dQ4$$eT3
000131548 592__ $$a0.234$$b2022
000131548 593__ $$aAtomic and Molecular Physics, and Optics$$c2022$$dQ4
000131548 594__ $$a1.7$$b2022
000131548 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000131548 700__ $$0(orcid)0000-0002-1827-1250$$aGarcía Rubio, I.$$uUniversidad de Zaragoza
000131548 700__ $$aVan Doorslaer, S.
000131548 7102_ $$12003$$2395$$aUniversidad de Zaragoza$$bDpto. Física Materia Condensa.$$cÁrea Física Materia Condensada
000131548 773__ $$g53 (2022), 1105-1119$$pAppl. magn. reson.$$tAPPLIED MAGNETIC RESONANCE$$x0937-9347
000131548 8564_ $$s1392992$$uhttps://zaguan.unizar.es/record/131548/files/texto_completo.pdf$$yVersión publicada
000131548 8564_ $$s1267218$$uhttps://zaguan.unizar.es/record/131548/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000131548 909CO $$ooai:zaguan.unizar.es:131548$$particulos$$pdriver
000131548 951__ $$a2024-03-18-12:45:49
000131548 980__ $$aARTICLE