Spectroscopy and Microscopy Studies of the Recognition of Amino Acids and Aggregation of Proteins by Zn(II) Complex of Lower Rim Naphthylidene Conjugate of Calix[4]arene
DSpace at IIT Bombay
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Title |
Spectroscopy and Microscopy Studies of the Recognition of Amino Acids and Aggregation of Proteins by Zn(II) Complex of Lower Rim Naphthylidene Conjugate of Calix[4]arene
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Creator |
CHINTA, JP
ACHARYA, A KUMAR, A RAO, CP |
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Subject |
bovine serum-albumin
zinc(ii) complexes gas-phase electrosprayed ions cysteine fragmentations homocysteine histidine zwitterions selectivity |
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Description |
A lower rim naphthylidene conjugate of calix[4]arene [L] has been synthesized and characterized, and the structure has been established on the basis of single crystal XRD. The L has been found to be selective toward Zn(2+), which induces appropriate changes in the arms of L so that the N(2)O(2) coordination results in the formation of a tetrahedral complex; namely, [ZnL]. [ZnL] recognizes Asp, Cys, His, and Glu from among the naturally occurring amino acids owing to the protonation and chelating ability of the amino acid and the pi-pi interaction ability of the side chain of the amino acid with [ZnL]. All of these features have been demonstrated oil the basis of fluorescence, absorption, and lifetime measurements. The rechelation of Zn(2+) by the amino acid used in the titration has been demonstrated on the basis of ESI-MS studies in the case of Cys to result in a Zn(2+) complex having either 5- or 6-coordination. [ZnL] has also been shown to be selective toward glutathione and glutathione oxidized, The amino acids present in the proteins also interact with [ZnL], resulting in dechelation of [ZnL] as well as aggregation of the protein, as demonstrated on the basis of absorption and fluorescence spectroscopy and atomic force microscopy. The alpha-helical proteins (namely, albumins) exhibit greater conformational changes, as compared to the beta-sheet proteins (namely, lectins), as studied oil the basis of CD spectroscopy, The aggregation of the proteins when treated with [ZnL] follows a trend: peanut agglutinin < bovine serum albumin < jacalin < human serum albumin. The present studies clearly demonstrated the recognition features of [ZnL] toward Asp, Cys, His, and Glu, and the peptides and proteins containing these by spectroscopy and microscopy studies.
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Publisher |
AMER CHEMICAL SOC
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Date |
2011-07-14T21:25:01Z
2011-12-26T12:47:38Z 2011-12-27T05:37:40Z 2011-07-14T21:25:01Z 2011-12-26T12:47:38Z 2011-12-27T05:37:40Z 2009 |
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Type |
Article
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Identifier |
JOURNAL OF PHYSICAL CHEMISTRY B, 113(35), 12075-12083
1520-6106 http://dx.doi.org/10.1021/jp903099b http://dspace.library.iitb.ac.in/xmlui/handle/10054/4073 http://hdl.handle.net/10054/4073 |
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Language |
en
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