Ionization state of the coenzyme 5'-phosphate ester in cytosolic aspartate aminotransferase. A Fourier transform infrared spectroscopic study

Sanchez-Ruiz, José M.; Martinez‐Carrion, Marino

doi:10.1021/bi00358a027

Cited by 27 publications

(12 citation statements)

References 17 publications

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“…The interaction of unlabeled ShB and ShB-L7E peptides with the anionic PA vesicles can also be assessed by monitoring the infrared absorbance bands at 1180 and 980 cm-1 arising from different stretching vibrations of the monoanionic and dianionic forms, respectively, of the PA phosphoryl group (Sanchez-Ruiz and Martinez-Carrion, 1986;Bhushan and McNamee, 1993). Monitoring of the pH dependence of the above infrared bands in plain PA vesicles, exactly as described by Bhushan and McNamee (1993), makes it possible to calculate a pKa of -8.0 corresponding to the deprotonation of the monoanionic phosphoryl group to produce the dianionic form (data not shown).…”

Section: Binding Of Peptides To Phospholipid Vesiclesmentioning

confidence: 99%

Interaction between ion channel-inactivating peptides and anionic phospholipid vesicles as model targets

Encinar

Fernández

Gavilanes

et al. 1996

Biophysical Journal

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Studies of rapid (N-type) inactivation induced by different synthetic inactivating peptides in several voltage-dependent cation channels have concluded that the channel inactivation "entrance" (or "receptor" site for the inactivating peptide) consists of a hydrophobic vestibule within the internal mouth of the channel, separated from the cytoplasm by a region with a negative surface potential. These protein domains are conformed from alternative sequences in the different channels and thus are relatively unrestricted in terms of primary structure. We are reporting here on the interaction between the inactivating peptide of the Shaker B K+ channel (ShB peptide) or the noninactivating ShB-L7E mutant with anionic phospholipid vesicles, a model target that, as the channel's inactivation "entrance," contains a hydrophobic domain (the vesicle bilayer) separated from the aqueous media by a negatively charged vesicle surface. When challenged by the anionic phospholipid vesicles, the inactivating ShB peptide 1) binds to the vesicle surface with a relatively high affinity, 2) readily adopts a strongly hydrogen-bonded beta-structure, likely an intramolecular beta "hairpin," and 3) becomes inserted into the hydrophobic bilayer by its folded N-terminal portion, leaving its positively charged C-terminal end exposed to the extravesicular aqueous medium. Similar experiments carried out with the noninactivating, L7E-ShB mutant peptide show that this peptide 1) binds also to the anionic vesicles, although with a lower affinity than does the ShB peptide, 2) adopts only occasionally the characteristic beta-structure, and 3) has completely lost the ability to traverse the anionic interphase at the vesicle surface and to insert into the hydrophobic vesicle bilayer. Because the negatively charged surface and the hydrophobic domains in the model target may partly imitate those conformed at the inactivation "entrance" of the channel proteins, we propose that channel inactivation likely includes molecular events similar to those observed in the interaction of the ShB peptide with the phospholipid vesicles, i.e., binding of the peptide to the region of negative surface potential, folding of the bound peptide as a beta-structure, and its insertion into the channel's hydrophobic vestibule. Likewise, we relate the lack of channel inactivation seen with the mutant ShB-L7E peptide to the lack of ability shown by this peptide to cross through the anionic interphase and insert into the hydrophobic domains of the model vesicle target.

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Section: Binding Of Peptides To Phospholipid Vesiclesmentioning

confidence: 99%

Interaction between ion channel-inactivating peptides and anionic phospholipid vesicles as model targets

Encinar

Fernández

Gavilanes

et al. 1996

Biophysical Journal

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“…W have recently shown that Fourier-transform infrared (FTIR)1 spectroscopy can be a valuable technique to determine the ionization state of protein-bound phosphoryl groups for coenzyme-dependent enzymes (Sanchez-Ruiz & Martinez-Carrion, 1986).…”

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confidence: 99%

A Fourier-transform infrared spectroscopic study of the phosphoserine residues in hen egg phosvitin and ovalbumin

Sanchez-Ruiz¹,

Martinez‐Carrion²

1988

Biochemistry

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A Fourier-transform infrared spectroscopic study of hen egg phosvitin and ovalbumin has been carried out. Bands arising from monoanionic and dianionic phosphate monoester [Shimanouchi, T., Tsuboi, M., & Kyogoku, Y. (1964) Adv. Chem. Phys. 8, 435-498] can be identified easily in the 1300-930 cm-1 region in spectra of solutions of O-phosphoserine and phosvitin, a highly phosphorylated protein. On the other hand, spectra of ovalbumin show a relatively strong absorption above 1000 cm-1 arising from the protein moiety. Below 1000 cm-1, a single band at 979 cm-1 is observed; this band is not present in spectra of dephosphorylated ovalbumin, and therefore, it has been assigned to the symmetric stretching of the phosphorylated Ser-68 and Ser-344 in the dianionic ionization state. In addition, bands arising from symmetric and antisymmetric stretchings of the monoanionic ionization state, and from the antisymmetric stretching of the dianionic state, can be detected above 1000 cm-1 in difference spectra of ovalbumin minus dephosphorylated ovalbumin. The effect of pH on the infrared spectra of O-phosphoserine, phosvitin, and ovalbumin is consistent with the phosphoserine residues undergoing ionization with pK values about 6. This study demonstrates that Fourier-transform infrared spectroscopy can be a useful technique to assess the ionization state of phosphoserine residues in proteins in solution.

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“…Pyridoxal phosphate-containing enzymes play an important role in the biological processes where they act as coenzymes catalyzing different reactions involved in the metabolism of amino acids. The biological potentialities of pyridoxal phosphate enzymes are determined, to a great extent, by the presence of an aldehyde and phenolic hydroxyl groups as well as pyridine nitrogen atom [1][2][3][4][5][6][7][8][9][10][11][12]. The aldehyde group is needed to form an external Schiff base with the substrate.…”

Section: Introductionmentioning

confidence: 99%

Conformational isomerism of pyridoxal. Infrared matrix isolation and theoretical studies

Kwiatek¹,

Mielke²

2015

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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Ionization state of the coenzyme 5'-phosphate ester in cytosolic aspartate aminotransferase. A Fourier transform infrared spectroscopic study

Cited by 27 publications

References 17 publications

Interaction between ion channel-inactivating peptides and anionic phospholipid vesicles as model targets

Interaction between ion channel-inactivating peptides and anionic phospholipid vesicles as model targets

A Fourier-transform infrared spectroscopic study of the phosphoserine residues in hen egg phosvitin and ovalbumin

Conformational isomerism of pyridoxal. Infrared matrix isolation and theoretical studies

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