Collagen fluorescence

Collagen fluorescence is associated with two types of cross-links. One is hydroxylysyl pyridinoline (HP) and another is lysyl pyridinoline (LP) [51] (Figure 20.11). Both are fluorescent with emission maximum at 400 nm when excited at 325 nm. 

Gold nanoparticles, both spheres or rods, quench collagen fluorescence by photonic absorption of the emission light of the fluorophore by the nanoparticles. The addition of Au nanospheres quenches the collagen fluorescence (Figure 20.13A) but it does not affect the absorption spectra of collagen (Figure 20.13B). 

Eluorescence of both collagen (Monnier etal., 1986) and IgG (Jones etal., 1988) are associated with diabetic micrOangiopathy. Monnier etal. (1986) found that measured collagen-linked fluorescence in skin biopsies from both patients with type 1 diabetes ( = 41, age range 29-52 years) and controls ( =25, age range 28-41 years) was significantly correlated with the severity of retinopathy as well as arterial and joint stifihess. Jones et al. (1988) found increased fluorescence of serum IgG in diabetic patients with... 

Monnier, V.M., Vishwaneth, V., Frank, K.E., Elmets, G.A., Dauchot, P. and Kohn, R.R. (1986). Relation between complications of type Iv diabetes mellitus and collagen-linked fluorescence. N. Engl. J. Med. 314, 403-408. 

Morimoto K, Kawabata K, Kunii S, Hamano K, Saito T, Tonomura B (2009) Characterization of type I collagen fibril formation using thioflavin T fluorescent dye. J Biochem 145(5) 677... 

Sakura, S. and Fujimoto, D. (1984) Absorbtion and fluorescence studies of tyrosine derived crosslinking amino acids from collagen. Photochemistry and Photobiology 40, 731-734. 

Fig. 9.7 Indirect immunofluorescent staining of SWCNTs-treated F1EK293 cells for day 1-5 by fluorescent microscopy (x 630). Green cadherin red collagen blue cellular nucleus staining with DAPI. The expression levels of cadherin and collagen IV in cells decreased gradually as the culture days increased F1EK293 cells gradually detached from the cell populations as the culture days increased (Grunlan et al., 2004. With permission from Elsevier) (See Color Plates)...

Figure 5. Fluorescence of collagen IV conjugated with Oregon Green 488 (Molecular Probes, Eugene, OR, USA.) spontaneously adsorbed to unmodified polyethylene foils (A) or polyethylene modified with 1014 0+ ions/cm at the energy of 30 keV (B). Collagen was diluted in phosphate-buffered saline to the concentration of 0.02 mg/ml (10 pg/cm ) and incubated with the foils for 24 h at room temperature. For auto fluorescence control.

Furosine and fluorescent cross-links (mol amino acid/ mol collagen, except pentosidine mmol/mol) determined by HPLC in hydrolyzates of dentin slices exposed to glucose and buffer, pH 7.4, and non-exposed controls (n=2). 

Fluorescence measurements. Collagenase digesfs (I) were dilufed in fhe appropriafe buffer in duplo fo 60 pg collagen equivalenfs per 3.0 ml, corresponding fo 200 pmol of collagen (MW 300 kDa). The following buffers were used ... 

Non-fluorescent amino acids were converted into fluorescence by a post-column reaction. Injection 67 pmol collagen of dentin hydrolyzates. 

HPLC of fluorescent amino acids from same hydrolyzate of sound (bottom) and carious (middle) dentin as in figure 2, and of a standard mixture (top). Compounds were detected after post-column acidification. Injection 167 pmol collagen of dentin hydrolyzates. 

Odetti P, Pronzato MA, Noberasco G, Cosso L, Traverso N, Cottalasso D and Marinari UM (1994) Relationships between glycation and oxidation related fluorescences in rat collagen during aging. Lab Invest 70, 61-67. 

In addition, peak VI (fig. 1) contained two compounds, one identified as lysinoalanine (table 1). Lysinoalanine is a well-known artefact of alkaline protein treatment but is supposed to be formed in dentin by the reaction between a collagen lysine- and a phosphoprotein phosphoserine residue (Fujimoto et al., 1981). Both compounds were not detected by HPLC after FMOC-derivatization, most likely because of fluorescence quenching inherent to the close vicinity of several FMOC groups attached to one molecule. Thus the unknown compound seems rather similar to lysinoalanine. We suggest the unknown compound is histidinoalanine, which is present in dentin (Fujimoto et al., 1982) and likely shows fluo-rence quenching in its FMOC derivate. 

Simon-Lukasik, K. V., Persikov, A. V., Brodsky, B., Ramshaw, J. A., Laws, W. R., Ross, A., and Ludescher, R. D. (2003). Fluorescence determination of tryptophan side-chain accessibility and dynamics in triple-helical collagen-like peptides. Biophys. J. 84, 501-508. 

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