Characterization of recombinant lysyl oxidase propeptide.
Lysyl oxidase enzyme activity is critical for the biosynthesis of mature and functional collagens and elastin. In addition, lysyl oxidase has tumor suppressor activity that has been shown to depend on the propeptide region (LOX-PP) derived from pro-lysyl oxidase (Pro-LOX) and not on lysyl oxidase enzyme activity. Pro-LOX is secreted as a 50 kDa proenzyme and then undergoes biosynthetic proteolytic processing to active approximately 30 kDa LOX enzyme and LOX-PP. The present study reports the efficient recombinant expression and purification of rat LOX-PP. Moreover, using enzymatic deglycosylation and DTT derivatization combined with mass spectrometry technologies, it is shown for the first time that rLOX-PP and naturally occurring LOX-PP contain both N- and O-linked carbohydrates. Structure predictions furthermore suggest that LOX-PP is a mostly disordered protein, which was experimentally confirmed in circular dichroism studies. Due to its high isoelectric point and its disordered structure, we propose that LOX-PP can associate with extracellular and intracellular binding partners to affect its known biological activities as a tumor suppressor and inhibitor of cell proliferation.
Vora
Siddharth R
SR
Department of Periodontology and Oral Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118, USA.
Guo
Ying
Y
Stephens
Danielle N
DN
Salih
Erdjan
E
Vu
Emile D
ED
Kirsch
Kathrin H
KH
Sonenshein
Gail E
GE
Trackman
Philip C
PC
D000818:Animals; D002942:Circular Dichroism; D003001:Cloning, Molecular / Q000379:methods; D004792:Enzyme Precursors; D006031:Glycosylation; D013058:Mass Spectrometry; D011485:Protein Binding; D011487:Protein Conformation; D008249:Protein-Lysine 6-Oxidase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D051381:Rats; D011994:Recombinant Proteins
D004792:Enzyme Precursors; D011994:Recombinant Proteins; D008249:Protein-Lysine 6-Oxidase