Structure Elucidation of Human Lens Proteins by Mass Spectrometry

1996 ◽  
pp. 223-235
Author(s):  
David L. Smith ◽  
Peiping Lin ◽  
Anders Lund ◽  
Jean B. Smith
Keyword(s):  
Mass Spectrometry ◽  
Structure Elucidation ◽  
Human Lens ◽  
Lens Proteins

Assigning in vivo carbamylation and acetylation in human lens proteins using tandem mass spectrometry and database searching

2007 ◽  
Vol 259 (1-3) ◽  
pp. 161-173 ◽  
Author(s):  
Zee-Yong Park ◽  
Rovshan Sadygov ◽  
Judy M. Clark ◽  
John I. Clark ◽  
John R. Yates
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Human Lens ◽  
Database Searching ◽  
Tandem Mass ◽  
Lens Proteins

scholarly journals Structure Elucidation of a Novel Yellow Chromophore from Human Lens Protein

2004 ◽  
Vol 279 (44) ◽  
pp. 45441-45449 ◽  
Author(s):  
Rongzhu Cheng ◽  
Qi Feng ◽  
Ognyan K. Argirov ◽  
Beryl J. Ortwerth
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Water Soluble ◽  
Human Lens ◽  
Lens Protein ◽  
Two Dimensional ◽  
Cross Link ◽  
Lens Proteins ◽  
Lysine Residues ◽  
Normal Human

We report here the isolation of a novel acid-labile yellow chromophore from the enzymatic digest of human lens proteins and the identification of its chemical structure by liquid chromatography-mass spectrometry, liquid chromatography-tandem mass spectrometry, and1H,13C, and two-dimensional NMR. This new chromophore exhibited a UV absorbance maximum at 343 nm and fluorescence at 410 nm when excited at 343 nm. Analysis of the purified compound by reversed-phase HPLC with in-line electrospray ionization mass spectrometry revealed a molecular mass of 370 Da. One- and two-dimensional NMR analyses elucidated the structure to be 1-(5-amino-5-carboxypentyl)-4-(5-amino-5-carboxypentylamino)-3-hydroxy-2,3-dihydropyridinium, a cross-link between the ϵ-amino groups of two lysine residues, and a five-carbon ring. Because this cross-link contains two lysine residues and a dihydropyridinium ring, we assigned it the trivial name of K2P. Quantitative determinations of K2P in individual normal human lens or cataract lens water-soluble and water-insoluble protein digests were made using a high-performance liquid chromatograph equipped with a diode array detector. These measurements revealed a significant enhancement of K2P in cataract lens proteins (613 ± 362 pmol/mg of water-insoluble sonicate supernatant (WISS) protein or 85 ± 51 pmol/mg of WS protein) when compared with aged normal human lens proteins (261 ± 93 pmol/mg of WISS protein or 23 ± 15 pmol/mg of water-soluble (WS) protein). These data provide chemical evidence for increased protein cross-linking during aging and cataract developmentin vivo. This new cross-link may serve as a quantitatively more significant biomarker for assessing the role of lens protein modifications during aging and in the pathogenesis of cataract.

Structure Elucidation of a Novel Family of Mycolactone Toxins from the Frog Pathogen Mycobacterium sp. MU128FXT by Mass Spectrometry.

ChemInform ◽  
2006 ◽  
Vol 37 (3) ◽  
Author(s):  
Hui Hong ◽  
Tim Stinear ◽  
Paul Skelton ◽  
Jonathan B. Spencer ◽  
Peter F. Leadlay
Keyword(s):  
Mass Spectrometry ◽  
Structure Elucidation
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