title: Aggregation and self assembly of non-enzymatic glycation of collagen in the presence of amino guanidine and aspirin: an in vitro study.
abstract: Non-enzymatic glycation of collagen has been used in modern biomaterials science. This paper deals with in vitro studies on the effects of amino guanidine (AG) and aspirin in the non-enzymatic glycation (NEG) of collagen using thermal, conformational, fluorescence, turbidity and powder XRD measurements. There is no significant change in the fluorescence emission spectra for different concentrations of AG treated NEG of collagen whereas the emission intensity decreases as the concentration of aspirin increases. Circular dichroism (CD) revealed the disappearance of the positive peak at 220nm for glycated collagen in the presence of amino guanidine and aspirin suggesting the collapse of triple helical configuration. Nearly 15 degrees C decrease is observed in shrinkage temperature of glycated rat tail tendon (RTT) collagen fibres in the presence of aspirin. Powder XRD of glycated collagen nano-fibrils in the presence of amino guanidine reveals high crystalline nature and the enhancement of self assembly processes when compared to aspirin. To the best of our knowledge, this is the first report of powder XRD of the self assembly of collagen nano-fibrils without mineralization. Our experimental results suggest that in the non-enzymatic glycation of collagen both AG and aspirin play a pivotal role in the aggregation and self assembly processes. From the present study, it is possible to conclude that while AG significantly influences the self assembly processes, aspirin facilitates the aggregation processes.
authors.affiliation: Biophysics Laboratory, Central Leather Research Institute, Council of Scientific and Industrial Research, Adyar, Chennai, India. usharamamoorthy54@yahoo.co.in
authors.forename: R
authors.initials: R
authors.lastname: Usha
authors.forename: S M
authors.initials: SM
authors.lastname: Jaimohan
authors.forename: A
authors.initials: A
authors.lastname: Rajaram
authors.forename: A B
authors.initials: AB
authors.lastname: Mandal
mesh_terms: D000042:Absorption; D000818:Animals; D001241:Aspirin / Q000494:pharmacology*; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D003094:Collagen / Q000737:chemistry / Q000378:metabolism*; D006031:Glycosylation / Q000187:drug effects; D006146:Guanidines / Q000494:pharmacology*; D009391:Nephelometry and Turbidimetry; D011487:Protein Conformation; D051381:Rats; D013050:Spectrometry, Fluorescence; D013696:Temperature; D014783:Viscosity; D014961:X-Ray Diffraction
chemical_list: D006146:Guanidines; D003094:Collagen; D001241:Aspirin; C004479:pimagedine