title: Inhibition of cryogelation by the novel synthetic peptide (Gly-Arg-Lys-Lys-Thr): recognition site of extra domain A containing fibronectin for heparin in cryogelation.
abstract: Cryogel is a physical gel formed by the heterophilic aggregation of extra domain A (EDA) containing fibronectin [EDA(+)FN], plasma fibronectin (pFN), fibrinogen (Fbg) and heparin (Hep) in the blood of rheumatoid arthritis (RA) patients. In cryogelation EDA(+)FN cross-links to form an interaggregate of cryogel with Hep. In the present study, we determined the recognition structure of Hep for EDA(+)FN by using oligo- and desulfonated-Hep. The affinity constant (KA) (1.2 x 10(8) per M) of oligo-Hep for EDA(+)FN did not change with a decrease in number-average molecular weight (4.9 x 10(4)-->6.0 x 10(3)). The KA-value of desulfonated-Hep for EDA(+)FN decreased from 3.2 x 10(8) to 1.0 x 10(7) per M with a decrease in the sulfonation ratio (7.0-->4.3%). We also determined the recognition structure of EDA(+)FN for Hep by an inhibition experiment on the heparin binding domain II (HepII) in EDA(+)FN with the synthetic peptides, Arg-Arg-Ala-Arg (RRAR), Asp-Gln-Ala-Arg (DNAR), Ile-Lys-Tyr-Glu-Lys (IKYEK), and Gly-Arg-Lys-Lys-Try (GRKKT). The GRKKT sequence clearly inhibited bonding between EDA(+)FN and Heps containing oligo- and desulfonated-Hep. The amount of cryogel formed in the RA-patient model plasma corresponded to the EDA(+)FN concentration in cryogel (36.7%) normalized by the EDA(+)FN concentration in plasma. When GRKKT was added to plasma, the EDA(+)FN concentration fell to 10.5%. These results demonstrated that inhibition of cryogelation in plasma could progress to a novel treatment for RA.
authors.affiliation: Department of Chemistry for Materials, Faculty of Engineering, Mie University, 1515 Kamihama, Tsu, Mie 514-8507, Japan. miyamoto@chem.mie-u.ac.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kobayashi
authors.forename: Rizu
authors.initials: R
authors.lastname: Maeda
authors.forename: Takaharu
authors.initials: T
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Komai
mesh_terms: D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry; D001172:Arthritis, Rheumatoid / Q000378:metabolism; D001798:Blood Proteins / Q000737:chemistry; D002240:Carbohydrate Sequence; D059985:Cryogels; D005353:Fibronectins / Q000737:chemistry*; D005615:Freezing; D005782:Gels / Q000737:chemistry; D005998:Glycine / Q000737:chemistry; D006493:Heparin / Q000737:chemistry*; D020100:Hydrogels; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008239:Lysine / Q000737:chemistry; D015233:Models, Statistical; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013912:Threonine / Q000737:chemistry; D013997:Time Factors
chemical_list: D001798:Blood Proteins; D059985:Cryogels; D005353:Fibronectins; D005782:Gels; D020100:Hydrogels; D010455:Peptides; D013912:Threonine; D006493:Heparin; D001120:Arginine; D008239:Lysine; D005998:Glycine