scholarly journals The molecular structure and lubricating activity of lubricin isolated from bovine and human synovial fluids

1985 ◽  
Vol 225 (1) ◽  
pp. 195-201 ◽  
Author(s):  
D A Swann ◽  
F H Silver ◽  
H S Slayter ◽  
W Stafford ◽  
E Shore
Keyword(s):  
Amino Acid ◽  
Synovial Fluid ◽  
Test System ◽  
Sedimentation Equilibrium ◽  
Human Knee ◽  
Synovial Fluids ◽  
Molecular Masses ◽  
Friction Measurements

Lubricin was isolated from bovine ankle, metacarpophalangeal and knee and human knee synovial fluids. The lubricins isolated from the bovine joint fluids had the same amino acid and carbohydrate compositions, but differences were observed in the relative molecular masses. The Mr values of bovine metacarpophalangeal and ankle lubricin determined by light-scattering measurements were about 200 000, whereas values of 132 000 and 143 000 were obtained for the bovine knee lubricin. The human knee lubricin had a similar carbohydrate composition to bovine knee lubricin except for the higher glucosamine content, and the amino acid composition differed slightly. The human sample had a lower glutamic acid content and a leucine/isoleucine ratio of 2:1 compared with 1:1 in the bovine. The Mr value of the human knee lubricin (166 000) was also lower than that of the bovine metacarpophalangeal and ankle samples. The Mr value of the bovine knee lubricin determined by sedimentation-equilibrium measurements was 171 000. The length measurements determined by electron microscopy and also the sedimentation measurements showed considerable polydispersity and indicate that the degree of extension of lubricin molecules can vary. Friction measurements showed that the human knee synovial-fluid lubricin had equivalent lubricating ability in a test system in vitro to that observed for lubricin isolated from normal bovine synovial fluids. The lubricating ability of lubricin was concentration-dependent, and each lubricin sample was able to act as a lubricant in vitro in an equivalent manner to whole synovial fluid at concentrations that are thought to occur in vivo.

Analysis of aggrecan in human knee cartilage and synovial fluid indicates that aggrecanase (ADAMTS) activity is responsible for the catabolic turnover and loss of whole aggrecan whereas other protease activity is required for C-terminal processing in vivo

2001 ◽  
Vol 358 (3) ◽  
pp. 615-626 ◽  
Author(s):  
John D. SANDY ◽  
Christie VERSCHAREN
Keyword(s):  
Synovial Fluid ◽  
Core Protein ◽  
Globular Domain ◽  
Human Cartilage ◽  
Human Knee ◽  
Synovial Fluids ◽  
Human Joints ◽  
Non Destructive

Studies of aggrecan proteolysis in human joints have implicated both the aggrecanase [ADAMTS, a disintegrin-like and metalloprotease (reprolysin-type) with thrombospondin type 1 motif] and matrix metalloproteinase (MMP) families. We have analysed the aggrecan core protein species present in vivo in both articular cartilage and synovial fluids from normal, acutely injured and osteoarthritic joints. Normal cartilage contains at least seven major G1 domain (the N-terminal globular domain of aggrecan)-bearing species, of which three (full-length core, G1-NITEGE373 and G1-VDIPEN341) have been identified. The C-terminals of the others are unknown but digestion of fetal human aggrecan with MMP-3 and crude aggrecanase suggests that they are products of MMP-like activity in vivo. Normal synovial fluids contain at least 10 species, of which nine result from ADAMTS-dependent cleavage, and this cleavage occurs at all of the five known aggrecanase sites. Aggrecan fragments in the cartilage and synovial fluids of acutely injured joints are generally similar to normal, but all contain a markedly increased ratio of G1-NITEGE to G1-VDIPEN. Aggrecan from the cartilage of late-stage osteoarthritis patients is remarkably similar to normal, whereas the synovial fluid aggrecan is more fragmented than that from normal or injured knees. The analyses suggest that the role of the ADAMTS and these MMP-like activities in human cartilage are distinctly different. Excessive ADAMTS activity in vivo is destructive to cartilage matrix, since the bulk of the glycosaminoglycan (GAG)-bearing products are released from the tissue into the synovial fluid following cleavage of the Glu373–Ala374 bond. In contrast, the MMP-like activity appears to be essentially non-destructive, since much of the GAG-bearing product is retained in the tissue following cleavages that are in the more C-terminal regions of the molecule.

Oxytocin analogues with non-coded amino acid residues in position 8: [8-Neopentylglycine]oxytocin and [8-cycloleucine]oxytocin

1987 ◽  
Vol 52 (9) ◽  
pp. 2317-2325 ◽  
Author(s):  
Jan Hlaváček ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Walter Y. Chan ◽  
Victor J. Hruby
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
The Other ◽  
Amino Acid Residues ◽  
Phase Synthesis ◽  
Other Hand ◽  
Fragment Condensation

[8-Neopentylglycine]oxytocin (II) and [8-cycloleucine]oxytocin (III) were prepared by a combination of solid-phase synthesis and fragment condensation. Both analogues exhibited decreased uterotonic potency in vitro, each being about 15-30% that of oxytocin. Analogue II also displayed similarly decreased uterotonic potency in vivo and galactogogic potency. On the other hand, analogue III exhibited almost the same potency as oxytocin in the uterotonic assay in vivo and in the galactogogic assay.

Synthesis of Fragments of the Vasoactive Intestinal Peptide (VIP) and Analysis of Their Residual Biological Activities

1995 ◽  
Vol 60 (7) ◽  
pp. 1229-1235 ◽  
Author(s):  
Ivana Zoulíková ◽  
Ivan Svoboda ◽  
Jiří Velek ◽  
Václav Kašička ◽  
Jiřina Slaninová ◽  
...  
Keyword(s):  
Amino Acid ◽  
Biological Activities ◽  
Residual Activity ◽  
Detailed Examination ◽  
Amino Acid Residues ◽  
Linear Peptide ◽  
Zone Electrophoresis ◽  
Capillary Zone

The vasoactive intestinal (poly)peptide (VIP) is a linear peptide containing 28 amino acid residues, whose primary structure indicates a low metabolic stability. The following VIP fragments, as potential metabolites, and their analogues were prepared by synthesis on a solid: [His(Dnp)1]VIP(1-10), VIP(11-14), [D-Arg12]VIP(11-14), [Lys(Pac)15,21,Arg20]VIP(15-22), and VIP(23-28). After purification, the peptides were characterized by amino acid analysis, mass spectrometry, RP HPLC, and capillary zone electrophoresis. In some tests, detailed examination of the biological activity of the substances in vivo and in vitro gave evidence of a low, residual activity of some fragments, viz. a depressoric activity in vivo for [His(Dnp)1]VIP(1-10) and a stimulating activity for the release of α-amylase in vitro and in vivo for [Lys(Pac)15,21,Arg20]VIP(15-22) and VIP(23-28).

scholarly journals An Evidence-Based Systematic Review of Human Knee Post-Traumatic Osteoarthritis (PTOA): Timeline of Clinical Presentation and Disease Markers, Comparison of Knee Joint PTOA Models and Early Disease Implications

2021 ◽  
Vol 22 (4) ◽  
pp. 1996 ◽  
Author(s):  
Christine M. Khella ◽  
Rojiar Asgarian ◽  
Judith M. Horvath ◽  
Bernd Rolauffs ◽  
Melanie L. Hart
Keyword(s):  
Synovial Fluid ◽  
Knee Joint ◽  
Ex Vivo ◽  
Disease Process ◽  
Early Disease ◽  
Knee Trauma ◽  
Post Traumatic ◽  
Acute Knee

Understanding the causality of the post-traumatic osteoarthritis (PTOA) disease process of the knee joint is important for diagnosing early disease and developing new and effective preventions or treatments. The aim of this review was to provide detailed clinical data on inflammatory and other biomarkers obtained from patients after acute knee trauma in order to (i) present a timeline of events that occur in the acute, subacute, and chronic post-traumatic phases and in PTOA, and (ii) to identify key factors present in the synovial fluid, serum/plasma and urine, leading to PTOA of the knee in 23–50% of individuals who had acute knee trauma. In this context, we additionally discuss methods of simulating knee trauma and inflammation in in vivo, ex vivo articular cartilage explant and in vitro chondrocyte models, and answer whether these models are representative of the clinical inflammatory stages following knee trauma. Moreover, we compare the pro-inflammatory cytokine concentrations used in such models and demonstrate that, compared to concentrations in the synovial fluid after knee trauma, they are exceedingly high. We then used the Bradford Hill Framework to present evidence that TNF-α and IL-6 cytokines are causal factors, while IL-1β and IL-17 are credible factors in inducing knee PTOA disease progresssion. Lastly, we discuss beneficial infrastructure for future studies to dissect the role of local vs. systemic inflammation in PTOA progression with an emphasis on early disease.

A novel polymorphism of human gene has an amino acid substitution (V365M) that decreases enzymatic activity in vitro and in vivo

2004 ◽  
Vol 76 (6) ◽  
pp. 519-527 ◽  
Author(s):  
T FUKAMI ◽  
M NAKAJIMA ◽  
R YOSHIDA ◽  
Y TSUCHIYA ◽  
Y FUJIKI ◽  
...  
Keyword(s):  
Amino Acid ◽  
Enzymatic Activity ◽  
Amino Acid Substitution ◽  
Human Gene

Reduced and S-carboxymethylated human growth hormone: a probe for diabetogenic action

1984 ◽  
Vol 247 (5) ◽  
pp. E639-E644
Author(s):  
C. M. Cameron ◽  
J. L. Kostyo ◽  
J. A. Rillema ◽  
S. E. Gennick
Keyword(s):  
Growth Hormone ◽  
Amino Acid ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Mouse Mammary Gland ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Hypophysectomized Rats

The biological activity profile of reduced and S-carboxymethylated human growth hormone (RCM-hGH) was determined to establish its suitability for study of the diabetogenic property of hGH. RCM-hGH was found to have greatly attenuated in vivo growth-promoting activity in the 9-day weight-gain test in hypophysectomized rats (approximately 1%) and to have a similar low order of in vitro activity in stimulating amino acid incorporation into the protein of the isolated rat diaphragm. RCM-hGH also only had approximately 1% of the in vitro insulin-like activity of the native hormone on isolated adipose tissue from hypophysectomized rats. In contrast, RCM-hGH retained substantial in vivo diabetogenic activity in the ob/ob mouse, appearing to have approximately 50% of the activity of the native hormone. RCM-hGH was also found to retain significant, although attenuated (25%), in vitro lactogenic activity when tested for the ability to stimulate amino acid incorporation into a casein-rich protein fraction in mouse mammary gland explants. Because RCM-hGH exhibits a high degree of diabetogenic activity, although lacking significant anabolic or insulin-like activities, it will be useful as a "monovalent" probe for the study of the molecular mechanism of the diabetogenic action of GH.

“In vivo” amplification of biological activity of tetragastrin by amino acid hydroxamates

1984 ◽  
Vol 4 (12) ◽  
pp. 1009-1015 ◽  
Author(s):  
J. P. Bali ◽  
H. Mattras ◽  
A. Previero ◽  
M. A. Coletti-Previero
Keyword(s):  
Biological Activity ◽  
Amino Acid ◽  
Aromatic Amino Acid ◽  
Aminopeptidase Activity ◽  
Proteolytic Degradation ◽  
Short Peptides ◽  
Rat Blood ◽  
Active Peptides

Rat blood was shown to contain an aminopeptidase which rapidly hydrolyses short peptides containing an aromatic amino acid as N-terminal residue. Using tetragastrin (Trp-Met-Asp-PheNH 2) as substrate, we showed that some amino acid hydroxamates inhibit rat aminopeptidase activity ‘in vitro’ in the following order: HTrpNHOH > HPheNHOH ≫ HAIaNHOH. The same hydroxamates markedly enhanced the biological activity of tetragastrin ‘in vivo’. The amplification of the secretory effect, correlated with the amount of the hydroxamate used, strongly suggests that these compounds can stabilize a number of active peptides in vivo by inhibiting their proteolytic degradation.

scholarly journals LASS3 (longevity assurance homologue 3) is a mainly testis-specific (dihydro)ceramide synthase with relatively broad substrate specificity

2006 ◽  
Vol 398 (3) ◽  
pp. 531-538 ◽  
Author(s):  
Yukiko Mizutani ◽  
Akio Kihara ◽  
Yasuyuki Igarashi
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Family Members ◽  
Fatty Acyl ◽  
Ceramide Synthase ◽  
Broad Substrate Specificity ◽  
Acid Protein ◽  
Amino Acid Protein

The LASS (longevity assurance homologue) family members are highly conserved from yeasts to mammals. Five mouse and human LASS family members, namely LASS1, LASS2, LASS4, LASS5 and LASS6, have been identified and characterized. In the present study we cloned two transcriptional variants of hitherto-uncharacterized mouse LASS3 cDNA, which encode a 384-amino-acid protein (LASS3) and a 419-amino-acid protein (LASS3-long). In vivo, [3H]dihydrosphingosine labelling and electrospray-ionization MS revealed that overproduction of either LASS3 isoform results in increases in several ceramide species, with some preference toward those having middle- to long-chain-fatty acyl-CoAs. A similar substrate preference was observed in an in vitro (dihydro)ceramide synthase assay. These results indicate that LASS3 possesses (dihydro)ceramide synthesis activity with relatively broad substrate specificity. We also found that, except for a weak display in skin, LASS3 mRNA expression is limited almost solely to testis, implying that LASS3 plays an important role in this gland.

scholarly journals Hsp90 Binds and Regulates the Ligand-Inducible α Subunit of Eukaryotic Translation Initiation Factor Kinase Gcn2

1999 ◽  
Vol 19 (12) ◽  
pp. 8422-8432 ◽  
Author(s):  
Olivier Donzé ◽  
Didier Picard
Keyword(s):  
Amino Acid ◽  
Constitutive Expression ◽  
Amino Acid Starvation ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Restrictive Temperature ◽  
Α Subunit ◽  
Macbecin I

ABSTRACT The protein kinase Gcn2 stimulates translation of the yeast transcription factor Gcn4 upon amino acid starvation. Using genetic and biochemical approaches, we show that Gcn2 is regulated by the molecular chaperone Hsp90 in budding yeast Saccharomyces cerevisiae. Specifically, we found that (i) several Hsp90 mutant strains exhibit constitutive expression of a GCN4-lacZ reporter plasmid; (ii) Gcn2 and Hsp90 form a complex in vitro as well as in vivo; (iii) the specific inhibitors of Hsp90, geldanamycin and macbecin I, enhance the association of Gcn2 with Hsp90 and inhibit its kinase activity in vitro; (iv) in vivo, macbecin I strongly reduces the levels of Gcn2; (v) in a strain expressing the temperature-sensitive Hsp90 mutant G170D, both the accumulation and activity of Gcn2 are abolished at the restrictive temperature; and (vi) the Hsp90 cochaperones Cdc37, Sti1, and Sba1 are required for the response to amino acid starvation. Taken together, these data identify Gcn2 as a novel target for Hsp90, which plays a crucial role for the maturation and regulation of Gcn2.

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