title: Specific interactions between cryogel components: role of extra domain A containing fibronectin in cryogelation.
abstract: Cryogel is a physical gel formed by heterophilic aggregation of extra domain A containing fibronectin [EDA(+)FN], plasma fibronectin (pFN), fibrinogen (Fbg) and heparin (Hep), which are found in high concentrations in the blood of patients suffering from rheumatoid arthritis. In this study, we clarify the specific interactions between cryogel components in terms of the affinity constant (K(A)), obtained by surface plasmon resonance (SPR). It is found that Fbg self-interactions occur at lower temperatures, and that K(A) of Fbg-Hep changes with temperature. Specifically, K(A) (2.0 x 10(8) [M(-1)]) of Fbg-Hep at 5 degrees C increases significantly from that (1.0x10(7) [M(-1)]) at 40 degrees C. K(A) of EDA(+)FN-Hep increases with temperature, by approximately 100-fold between 40 degrees C (K(A)=10(12) [M(-1)]) and 20 degrees C (K(A)=10(10) [M(-1)]). Although K(A) of the FN fragments of Hep-binding domain containing an EDA region [EDA(+)HBD(+)] and Hep increases with temperatures above 30 degrees C, K(A)s of HBD(+)-Hep and EDA(+)-Hep are not temperature-dependent. Therefore, EDA(+)HBD(+), formed as a special structure for high Hep affinity, exhibits temperature-dependent interaction with Hep. These results suggest that the main role of EDA(+)FN in cryogelation is to support the interaction with Hep.
authors.affiliation: Department of Chemistry for Materials, Faculty of Engineering, Mie University, 1515 Kamihama-Cho, Tsu, Mie 514-8507, Japan. miyamoto@chem.mie-u.ac.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Nagisa
authors.initials: N
authors.lastname: Kodera
authors.forename: Hayato
authors.initials: H
authors.lastname: Umekawa
authors.forename: Yukio
authors.initials: Y
authors.lastname: Furuichi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tokita
authors.forename: Takashi
authors.initials: T
authors.lastname: Komai
mesh_terms: D001665:Binding Sites; D001798:Blood Proteins / Q000737:chemistry*; D059985:Cryogels; D005353:Fibronectins / Q000737:chemistry* / Q000378:metabolism; D005782:Gels / Q000737:chemistry*; D006493:Heparin / Q000737:chemistry; D006801:Humans; D020100:Hydrogels; D009391:Nephelometry and Turbidimetry; D010949:Plasma / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D020349:Surface Plasmon Resonance
chemical_list: D001798:Blood Proteins; D059985:Cryogels; D005353:Fibronectins; D005782:Gels; D020100:Hydrogels; D006493:Heparin