Studies on the molecular significance in the interaction of bilirubin with collagen.
The present investigation is aimed to understand the physiological significance of bilirubin interaction with collagen. In human skin, collagen absorbs both free bilirubin and serum bound bilirubin from the human system. Interaction between bilirubin and collagen depends on time, temperature and concentration of bilirubin. There is an increase in the aggregation rate of collagen in the presence of biliruibin. At physiological condition, 125 nM of bilirubin is the maximum concentration absorbed by per mg of collagen molecule. Bilirubin accelerates the lateral growth of collagen fibrils by shifting its rate of nucleation. Moreover, collagen-bilirubin complex exhibit a tendency to undergo adsorption onto the surface of the fibroblast cells, showing detrimental effects on fibroblasts proliferations. Based on the collagen binding assays, the binding of bilirubin to collagen is found to be electrostatic in nature, which confirms binding between the amino acid fragment of α1 (I) region of collagen and carboxyl group of bilirubin. The biotinylated bilirubin derivatives show better binding to α1 (I) chain rather than α2 (I) chains which clearly designates that bilirubin shows greater affinity to α1 chains of collagen. This novel approach directs to reduce the occurrence of bilirubin in hyperbilirubinemia patients.
Central Leather Research Institute, Council of Scientific and Industrial Research, Adyar, Chennai 600 020, India; National Institute for Materials Science, Tsukuba, Japan.
Usharani
U
Nagarajan
Jayakumar
J
Gladstone Christopher
Bangaru
B
Chandrasekaran
Raghava Rao
RR
Jonnalagadda
Unni Nair
UN
Balachandran
Kawakami
K
Kohsaku
D000818:Animals; D001663:Bilirubin / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D003094:Collagen / Q000737:chemistry / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D011485:Protein Binding; D051381:Rats; D013696:Temperature
D003094:Collagen; D001663:Bilirubin
Bilirubin; Collagen; Collagen binding assay