scholarly journals Interaction of cartilage proteoglycans with hyaluronic acid. The role of the hyaluronic acid carboxyl groups

1977 ◽  
Vol 167 (3) ◽  
pp. 711-716 ◽  
Author(s):  
J E Christner ◽  
M L Brown ◽  
D D Dziewiatkowski
Keyword(s):  
Hyaluronic Acid ◽  
Methyl Ester ◽  
Binding Capacity ◽  
Methyl Esters ◽  
Binding Activity ◽  
Carboxyl Groups ◽  
Nasal Cartilage ◽  
Carboxylate Groups ◽  
Glycine Methyl Ester ◽  
Cartilage Proteoglycans

Hyaluronic acid-derived oligomers of five to fifteen repeat dissaccharides effectively bind to bovine nasal-cartilage proteoglycan and inhibit the interaction between proteoglycans and high-molecular-weight hyaluronic acid. If, however, the hyaluronic acid oligosaccharides are modified by reaction with diazomethane to form the carboxyl methyl esters of the glucuronic acid residues, their inhibitory activity is abolished. The binding capacity can be fully restored by saponification. The amide derivative, which is formed by condensation of the oligosaccharide carboxyl groups with glycine methyl ester, is also ineffective in blocking the proteoglycan-hyaluronic acid interaction. In this case, binding activity is not restored when the amidated oligomers are subjected to saponification to yield the free carboxylate groups on the glycine residues. Thus the displacement of the carboxylate groups on the polysaccharide chain by the interposition of a glycine residue blocks the interaction between the proteoglycans and the hyaluronic acid oligomers. When the oligosaccharide methyl ester is reduced with NaBH4, the resultant glucose-containing oligomers exhibit decreased binding to proteoglycans. Thus it appears that the hyaluronic acid carboxylate anion in a specific spatial orientation is required for hyaluronic acid-proteoglycan interaction.

scholarly journals Positive Charges on Lysine Residues of the Extrinsic 18 kDa Protein Are Important to Its Electrostatic Interaction with Spinach Photosystem II Membranes

2005 ◽  
Vol 37 (11) ◽  
pp. 737-742 ◽  
Author(s):  
Jin-Peng Gao ◽  
Zhen-Hua Yong ◽  
Feng Zhang ◽  
Kang-Cheng Ruan ◽  
Chun-He Xu ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Methyl Esters ◽  
Binding Activity ◽  
Water Soluble ◽  
Carboxyl Groups ◽  
Amino Groups ◽  
Charged Amino Acids ◽  
Lysine Residues ◽  
Glycine Methyl Ester ◽  
Positively Charged

Abstract To determine the contribution of charged amino acids to binding with the photosystem II complex (PSII), the amino or carboxyl groups of the extrinsic 18 kDa protein were modified with Nsuccinimidyl propionate (NSP) or glycine methyl ester (GME) in the presence of a water-soluble carbodiimide, respectively. Based on isoelectric point shift, 4–10 and 10–14 amino groups were modified in the presence of 2 and 4 mM NSP, respectively. Similarly, 3–4 carboxyl groups were modified by reaction with 100 mM GME. Neutralization of negatively charged carboxyl groups with GME did not alter the binding activity of the extrinsic 18 kDa protein. However, the NSP-modified 18 kDa protein, in which the positively charged amino groups had been modified to uncharged methyl esters, failed to bind with the PSII membrane in the presence of the extrinsic 23 kDa protein. This defect can not be attributed to structural or conformational alterations imposed by chemical modification, as the fluorescence and circular dichroism spectra among native, GME and NSP-modified extrinsic 18 kDa proteins were similar. Thus, we have concluded that the positive charges of lysyl residues in the extrinsic 18 kDa protein are important for its interaction with PSII membranes in the presence of the extrinsic 23 kDa protein. Furthermore, it was found that the negative charges of carboxyl groups of this protein did not participate in binding with the extrinsic 23 kDa protein associated with PSII membranes.

scholarly journals Immunochemical analysis of cartilage proteoglycans. Cross-reactivity of molecules isolated from different species

1981 ◽  
Vol 199 (1) ◽  
pp. 81-87 ◽  
Author(s):  
J Wieslander ◽  
D Heinegård
Keyword(s):  
Hyaluronic Acid ◽  
Articular Cartilage ◽  
Chondroitin Sulphate ◽  
Limb Bud ◽  
Binding Region ◽  
Human Cartilage ◽  
Nasal Cartilage ◽  
Cartilage Proteoglycans ◽  
Rabbit Articular Cartilage ◽  
Hyaluronic Acid Binding

Antibodies directed against whole bovine nasal-cartilage proteoglycan and against the hyaluronic acid-binding region and chondroitin sulphate peptides from the same molecule were used in immunodiffusion and immunoelectromigration experiments. Proteoglycans from bovine nasal and tracheal cartilage showed immunological identity, with all three antisera. Proteoglycans from pig hip articular cartilage, dog hip articular cartilage, human tarsal articular cartilage and rat chondrosarcoma reacted with all the antisera and showed immunological identity with the corresponding structures isolated from bovine nasal-cartilage proteoglycans. In contrast, proteoglycans from rabbit articular cartilage, rabbit nasal cartilage and cultured chick limb buds did not react with the antibodies directed against the hyaluronic acid-binding region, though reacting with antibodies raised against whole proteoglycan monomer and against chondroitin sulphate peptides. All the proteoglycans gave two precipitation lines with the anti-(chondroitin sulphate peptide) antibodies. Similarly, the proteoglycans reacting with the anti-(hyaluronic acid-binding region) antibodies gave two precipitation lines. The results indicate the presence of at least two populations of aggregating proteoglycan monomers in cartilage. The relative affinity of the antibodies for cartilage proteoglycans and proteoglycan substructures from various species was determined by radioimmunoassay. The affinity of the anti-(hyaluronic acid-binding region) antibodies for the proteoglycans decreased in the order bovine, dog, human and pig cartilage. Rat sternal-cartilage and rabbit articular-cartilage proteoglycans reacted weakly, whereas chick limb-bud and chick sternal-cartilage proteoglycans did not react. In contrast, the affinity of antibodies to chondroitin sulphate peptides for proteoglycans increased in the order bovine cartilage, chick limb bud and chick sternal cartilage, dog cartilage, rat chondrosarcoma, human cartilage, pig cartilage, rat sternal cartilage and rabbit cartilage.

Sequence Determination of a Protein with N-Terminal Glutamic Acid after Modification of Carboxyl Groups with Carbodiimide as the Coupling Agent

1974 ◽  
Vol 52 (6) ◽  
pp. 560-562
Author(s):  
C. Gilardeau ◽  
M. Chrétien
Keyword(s):  
Methyl Ester ◽  
Glutamic Acid ◽  
Water Soluble ◽  
Carboxyl Groups ◽  
Edman Degradation ◽  
Sequence Determination ◽  
Glutamic Acid Residue ◽  
N Terminus ◽  
Glycine Methyl Ester

Glutamine and asparagine residues in proteins can be differentiated from glutamic and aspartic residues, during the Edman degradation, after modification of the carboxyl groups by glycine methyl ester in presence of a water-soluble carbodiimide. When applied to ovine and porcine beta-lipotropic hormones, which have a glutamic acid residue at the N-terminus, the carbodiimide blocks the N-terminus. However, the Edman degradation proceeds normally, if the phenylthiocarbamyl derivative is formed prior to the modification reaction with glycine. In this communication, radioactive glycine was used to modify the carboxyl groups.

scholarly journals Relationship between isoelectric point of native and chemically modified insulin and liposomal fusion

1989 ◽  
Vol 264 (1) ◽  
pp. 285-287 ◽  
Author(s):  
R N Farías ◽  
A E López Viñals ◽  
E Posse ◽  
R D Morero
Keyword(s):  
Methyl Ester ◽  
Isoelectric Point ◽  
Carboxyl Groups ◽  
Amino Groups ◽  
Chemically Modified ◽  
Glycine Methyl Ester ◽  
Native Insulin ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Fusion Ability

Native insulin causes fusion of negatively charged liposomes in the pH range from 3.0 to 5.5. In marked contrast, insulin with all three amino groups succinylated did not show fusion ability at any pH. On the other hand, insulin amidated with glycine methyl ester with all six carboxyl groups blocked shifted its activity to higher pH, showing a pH range of activity from 3.0 to 7.4. When the carboxyl groups were recovered by hydrolysis of methoxyl groups from glycine methyl ester-treated insulin, the protein obtained (glycyl-insulin with six free carboxyl groups) behaved as native insulin. A good correlation between the isoelectric point values of insulin and its derivatives and their fusion properties was found.

Lipotropic and Adrenocorticotropic Hormones. Biological Activities of the Carboxyl-Modified Hormones

1974 ◽  
Vol 52 (3) ◽  
pp. 723-726 ◽  
Author(s):  
C. Gilardeau ◽  
M. Chrétien ◽  
M. Lis
Keyword(s):  
Methyl Ester ◽  
Coupling Agent ◽  
Lipolytic Activity ◽  
Biological Activities ◽  
Water Soluble ◽  
Carboxyl Groups ◽  
Glycine Methyl Ester

The carboxyl groups of sheep adrenocorticotropic and beta-lipotropic hormones (ACTH and beta-LPH) were modified by glycine methyl ester and taurine using a water-soluble carbodiimide as a coupling agent. The biological activities of these derivatives were measured and compared with those of the native hormones. With ACTH, the lipolytic activity is almost unaffected although the adrenocorticotropic activity is completely destroyed. LPH partially looses its lipolytic activity.

scholarly journals Assembly of proteoglycan aggregates in cultures of chondrocytes from bovine tracheal cartilage

1981 ◽  
Vol 199 (1) ◽  
pp. 17-29 ◽  
Author(s):  
S Björnsson ◽  
D Heinegård
Keyword(s):  
Hyaluronic Acid ◽  
Cell Cultures ◽  
Low Ph ◽  
Link Protein ◽  
Nasal Cartilage ◽  
Cartilage Proteoglycan ◽  
Proteoglycan Aggregates ◽  
Cartilage Proteoglycans ◽  
Free Monomer

The assembly of proteoglycan aggregates in chondrocyte cell cultures was examined in pulse-chase experiments with the use of [35S]sulphate for labelling. Rate-zonal centrifugation in linear sucrose density gradients (10-50%, w/v) was used to separate the aggregated proteoglycans from monomers and to assess the size of the newly formed aggregates. The proportion of aggregates stabilized by link protein was assessed by competition with added exogenous aggregate components. The capacity of the proteoglycans synthesized in culture to compete with exogenous nasal-cartilage proteoglycans for binding was studied in dissociation-reassociation experiments. The results were as follows. (a) The proteoglycan monomers and the hyaluronic acid are exported separately and combined extracellularly. (b) The size of the aggregates increases gradually with time as the proportion of monomers bound to hyaluronic acid increases. (c) All of the aggregates present at a particular time appear to be link-stabilized and therefore not dissociated by added excess of nasal-cartilage proteoglycan monomer or hyaluronic acid oligomers. (d) The free monomer is apparently present as a complex with link protein. The monomer-link complexes are then aggregated to the hyaluronic acid. (e) The aggregates synthesized in vitro and the nasal-cartilage aggregates differ when tested for link-stabilization by incubation at low pH. The aggregates synthesized in vitro were completely dissociated whereas the cartilage proteoglycans remained aggregated. The results obtained from dissociation-reassociation experiments performed at low pH indicate that the proteoglycan monomer synthesized in vitro does not bind the hyaluronic acid or the link protein as strongly as does the nasal-cartilage monomer.

Activity of Plasmin and Streptokinase-Activator on Substituted Arginine and Lysine Esters

1966 ◽  
Vol 16 (01/02) ◽  
pp. 018-031 ◽  
Author(s):  
S Sherry ◽  
Norma Alkjaersig ◽  
A. P Fletcher
Keyword(s):  
Molecular Structure ◽  
Methyl Ester ◽  
Comparative Studies ◽  
Esterase Activity ◽  
Methyl Esters ◽  
Hydrolytic Activity ◽  
The Other ◽  
Other Hand

SummaryComparative studies have been made of the esterase activity of plasmin and the streptokinase-activator of plasminogen on a variety of substituted arginine and lysine esters. Human plasmin preparations derived by different methods of activation (spontaneous in glycerol, trypsin, streptokinase (SK) and urokinase) are similar in their esterase activity; this suggests that the molecular structure required for such esterase activity is similar for all of these human plasmins. Bovine plasmin, on the other hand, differs from human plasmin in its activity on several of the substrates studied (e.g., the methyl esters of benzoyl arginine and tosyl, acetyl and carbobenzoxy lysine), a finding which supports the view that molecular differences exist between the two animal plasmins. The streptokinase-activator hydrolyzes both arginine and lysine esters but the ratios of hydrolytic activity are distinct from those of plasmin and of other activators of plasminogen. The use of benzoyl arginine methyl ester as a substrate for the measurement of the esterase activity of the streptokinase-activator is described.

Synthesis of oxytocin analogues modified in the tripeptide side-chain by condensation of aminoterminal linear hexapeptide with the carboxyterminal tripeptide

1979 ◽  
Vol 44 (1) ◽  
pp. 275-287 ◽  
Author(s):  
Jan Hlaváček ◽  
Tomislav Barth ◽  
Karel Bláha ◽  
Karel Jošt
Keyword(s):  
Methyl Ester ◽  
Side Chain ◽  
Glycine Methyl Ester

For the synthesis of oxytocin (Ia) analogues modified in the carboxyterminal part of the molecule, a method based on the condensation of protected aminoterminal hexapeptide with tripeptides by the action of dicyclohexylcarbodiimide and pentafluorophenol in the presence of 1-hydroxybenzotriazole was devised. Using this method [7-[U-13C]proline]oxytocin (Ib), des-9-glycine-oxytocin (Ic) and methyl ester of oxytocinoic acid ([9-glycine methyl ester]oxytocin) (Id) were prepared.

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