INFLUENCE OF ALLOSTERIC EFFECTORS ON THE HEME CONFORMATION OF DROMEDARY FERROUS NITROSYLHEMOGLOBIN DETECTED BY XANES SPECTROSCOPY

被引：5

作者：

CASTELLANO, AC

DELLALONGA, S

BIANCONI, A

BARTERI, M

BURATTINI, E

ASCENZI, P

COLETTA, M

SANTUCCI, R

AMICONI, G

机构：

[1] UNIV TURIN, DEPT PHARMACEUT CHEM & TECHNOL, I-10124 TURIN, ITALY

[2] UNIV CAMERINO, NATL LABS, I-62032 CAMERINO, ITALY

[3] UNIV ROME LA SAPIENZA, DEPT CHEM, I-00185 ROME, ITALY

[4] UNIV ROME LA SAPIENZA, DEPT BIOCHEM SCI, CTR MOLEC BIOL, CNR, I-00185 ROME, ITALY

[5] IST NAZL FIS NUCL, DEPT MOLEC CELLULAR & ANIM BIOL, FRASCATI, ITALY

[6] UNIV LAQUILA, DEPT EXPTL MED, I-67100 LAQUILA, ITALY

[7] CNR, FRASCATI, ITALY

来源：

BIOCHIMICA ET BIOPHYSICA ACTA | 1991年 / 1080卷 / 02期

关键词：

DROMEDARY HEMOGLOBIN; FERROUS NITROSYLHEMOGLOBIN; XANES SPECTROSCOPY; (CAMELUS-DROMEDARIUS);

D O I：

10.1016/0167-4838(91)90137-O

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The changes of the Fe heme-active site conformation of dromedary (Camelus dromedarius) nitrosylhemoglobin (HbNO) induced by inositol hexakisphosphate (IHP) and chlofibric acid (CFA) have been studied by using X-ray absorption near-edge structure (XANES) spectroscopy. Structural information has been determined by multiple scattering analysis of the Fe K-edge XANES spectra. The proximal histidine is found to move away from iron centers by about 0.4 angstrom on the average over the four hemes upon binding of CFA or stoichiometric amount of IHP. In molar excess of polyanion or in the simultaneous presence of IHP, CFA and chloride, the proximal histidine moves back to a position very close to that observed in pure buffer; yet, the structure modulation induced by the allosteric effectors is not completely reversible. Such findings parallel with the functional properties and the spectroscopic (e.g., EPR and absorbance) characteristics of HbNO.

引用

页码：119 / 125

页数：7

共 60 条

[1] EVIDENCE FOR 2 OXYGEN-LINKED BINDING-SITES FOR POLYANIONS IN DROMEDARY HEMOGLOBIN [J].