Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pepsin digests of human post-burn wound tissues grafted with autologous fresh skin showed a significantly lower ratio, 0.37 +/- 0.04 (mean +/- S.D.), of type III to type I collagen determined by interrupted gel electrophoresis than the ratio, 0.55 +/- 0.13, measured in ungrafted wound tissues (p less than 0.001). In wounds grafted with frozen skin there was no significant difference from ungrafted wounds, but a significantly higher ratio, 0.46 +/- 0.08, than that in wounds grafted with fresh skin (p less than 0.001). These results were consistent with the histological features of the wound tissues.
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PMID:The effect of skin grafts on the ratio of collagen types in human post-burn wound tissues. 621 8

Fibril formation of neutral salt soluble and pepsin-treated type I collagen from rabbit corneal stroma or sclera was compared using a turbidimetric analysis which permits the determination of apparent rate constants and activation energies for the lag and growth phase of collagen fibrillogenesis. Information regarding the lateral growth of fibrils was obtained from the final turbidity values. Neutral salt soluble corneal collagen had smaller rate constants for both the lag and growth phases of fibrillogenesis than scleral collagen. Pepsin treatment decreased the rate constants for both collagens proportionately. The activation energies were higher for type I collagen from cornea than sclera. Pepsin treatment increased the activation energy for both phases of corneal fibril formation but only the growth phase of scleral collagen fibrillogenesis was affected. The extent of lateral fibril growth was compared using the intrinsic turbidity values which are related to the mass per unit fibril length. Neutral salt soluble scleral type I collagen had a significantly higher intrinsic turbidity than did neutral salt soluble corneal collagen indicating that scleral collagen formed thicker fibrils; however, this difference was not retained after pepsin treatment, demonstrating that a helical-telopeptide interaction occurs in corneal type I collagen which influences fibril diameter. The observed differences in the rate constants, activation energies and intrinsic turbidity values indicates that there are molecular differences which are responsible for fibrillar differences of corneal and scleral type I collagens.
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PMID:Kinetic analysis of collagen fibrillogenesis: II. Corneal and scleral type I collagen. 647 70

We studied biochemically the changes associated with aging and disease in the collagen of articular cartilages and menisci. Pepsin soluble and insoluble collagen were obtained by the method of Miller (1971) from the articular cartilages of seven healthy young and adult, six healthy aged subjects, and of six osteoarthritic and six rheumatoid arthritic patients. One portion of pathological cartilage was histologically examined to eliminate any possible contamination of the fibrous tissue and subchondral bone, and to classify the pathological findings. By the method of Miller, the pepsin soluble and insoluble collagen were also obtained from four adult and six aged menisci. Amino acid composition and carbohydrate contents were studied in insoluble collagen. The type of soluble collagen were analyzed with SDS disc electrophoresis. The amount of crosslinks in insoluble collagen was analyzed by the method of Masuda (1976) using automatic amino acid analyzer. The results obtained where shown as follow: 1) Solubility of collagen by pepsin decreased with aging on articular cartilages and menisci. In osteoarthritis and rheumatoid arthritis, the solubility of collagen by pepsin was different between the samples, and generally higher than that of collagen from the aged articular cartilages. 2) In respect to aldimine crosslinks of insoluble collagen, the dihydroxylysinonorleucine (DHLNL), hydroxylysinonorleucine (HLNL) and lysinonorleucine (LNL) increased with aging. DHLNL and HLNL were present in the nonreduced collagen in vitro. It was shown that the aldimine crosslinks had been already reduced in vivo. 3) The contents of carbohydrate of insoluble collagen from articular cartilage showed lower values than that of type II collagen as described previously. The hexosamine contents increased and those of uronic acid and hexose decreased with aging. In osteoarthritic and rheumatoid arthritic articular cartilages, the contents of uronic acid were lower than that of healthy aged group. The carbohydrate contents of menisci were similar to that of type I collagen. 4) concerning the type of collagen, healthy articular cartilages consisted of type II collagen. In collagen of aged cartilages and those of fibrillated and osteophytic cartilages in osteoarthritic and rheumatoid arthritic patients, the type II collagen were mixed with type I collagen ranging from 13.8% to 64.5%, although the analysis of articular cartilages in this study showed histological characteristics of hyaline cartilage. The type of soluble collagen in adult and aged menisci were composed of type I collagen in spite of aging.
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PMID:[Biochemical study of human articular cartilage and meniscus on aging and joint disease (author's transl)]. 689 84

The influence of tissue pretreatment on the PAP immunostaining for type I and III collagens and tenascin was studied in formalin-fixed and paraffin-embedded human tooth germs at the 24th and 25th weeks of fetal life. Three variables were considered: the type of buffer used (PBS or Tris), pepsin digestion and the use of normal serum as a blocking agent prior to immunostaining. All three proteins needed an enzymatic digestion to be intensely revealed. Pepsin promoted, even at low concentrations, an intracellular staining of type I collagen in the secretory odontoblasts and in the pulpal fibroblasts. Normal serum partially blocked unspecific immunoreaction when polyclonal rabbit antibodies were used. The Tris buffer increased the staining intensity of the three macromolecules and revealed an unusual tenascin-like immunoreactivity in the ameloblasts. This study demonstrated that pepsin digestion and the use of normal serum and different buffers may influence the immunoreactivity of ECM proteins.
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PMID:The influence of tissue pretreatment on the immunohistochemical demonstration of type I and III collagens and tenascin in fetal human tooth germs. 769 Nov 42

Previous studies have shown that pulmonary surfactant protein D (SP-D) is composed of a 43-kDa polypeptide with a short NH2-terminal domain, a collagen sequence, and a COOH-terminal C-type lectin domain. In the present studies, ultrastructural and biochemical techniques were used to examine the quaternary structure of native rat SP-D (rSP-D). Electron microscopy of freeze-dried preparations demonstrated a highly homogeneous population of molecules with four identical rod-like arms (46 nm in length), each with an 8-9-nm diameter globular terminal expansion. The arms, which are similar in diameter to the type I collagen helix (approximately 4 nm), emanate from the central "hub" in two pairs that closely parallel each other for their first 10 nm. This structure is consistent with hydrodynamic studies that predict an highly asymmetric and extended molecule (f/f0 = 3.26) with a large Stokes radius (Rs = 18 nm). Pepsin digestion gave glycosylated, trimeric collagenous fragments (43 +/- 4 nm, 17 kDa/chain). Trimeric subunits containing intact triple helical domains were also liberated from SP-D dodecamers by sulfhydryl reduction under non-denaturing conditions. Digestion of rSP-D with bacterial collagenase generated a COOH-terminal carbohydrate binding fragment and a smaller peptide (approximately 12 kDa, unreduced) that contains interchain disulfide bonds. Electron microscopy also demonstrated higher orders of multimerization, with as many as 8 molecules associated at the hub. These studies demonstrate that SP-D is assembled as homopolymers of four identical trimeric subunits, that interactions between the amino-terminal domains of the trimers are stabilized by interchain disulfide bonds, and that SP-D molecules can associate to form complex multimolecular assemblies.
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PMID:Molecular structure of pulmonary surfactant protein D (SP-D). 800 40

The tissue engineering area henceforth calls more and more for bioabsorbable substrata made of biopolymers (collagen, laminin...) or polymers (PLA, PLGA, PGA...) to realize the three-dimensional culture of tissue equivalents. The poly (beta-hydroxybutyrate-beta-hydroxyvalerate), a biopolymer considered as being biodegradable and biocompatible, has been recently introduced for orthopaedic biomaterials and regeneration purposes. In our study, a PHB/9% HV polymer was transformed into 3D foams, then applied to the culture 3D of ovine chondrocytes (fibrous rings & growth plates) and osteoblasts (periostum). Sponges made of bovine type I collagen were used as references. Orthopaedic cells were isolated, prepared and sown by simple injection to the geometrical center of the substrata, then incubated from 0 to 35 days by changing the culture medium all 4 days. Maximal densities were reached after 21 days: 18-24.10(6) cells/g for the chondrocytes, 8-10.10(6) cells/g for the osteoblasts. The cellular proliferation was more marked, with highest cell densities, for the collagen sponges. Laser confocal microscopy shows that the cellular diffusion take place throughout the entire volume of the porous artificial substrata. Future studies will allow to apply the porous bioabsorbable substrata to high-density cell cultures, to the tissue engineering and regeneration, for example for orthopaedic tissues: cartilage, fibrocartilage and bone.
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PMID:[Bio-absorbable synthetic polyesters and tissue regeneration. A study of three-dimensional proliferation of ovine chondrocytes and osteoblasts]. 903 39

The alpha2 chain of canine type I collagen was characterized with both sequence analysis of COL1A2 cDNA and chemical analysis of alpha2(I) chains. The complete sequence of canine COL1A2 cDNA was determined from reverse-transcribed and polymerase chain reaction-amplified total RNA from cultured skin fibroblasts. Pepsin-digested and cyanogen bromide-digested type I collagen peptides were analyzed with chromatography, gel electrophoresis, and mass spectrometry. Identity between the sequences of canine and human COL1A2 cDNA was 90.9%, predicting conservation of the 3 cysteine residues required for C-propeptide registration and of cleavage sites for signal peptidase, procollagen N-proteinase, vertebrate collagenase, and procollagen C-proteinase. Conservation of all 50 lysine residues was also predicted, including preservation of the 1:2 asymmetry in the X:Y distribution of the 31 lysine residues in the alpha2(I) triple helix. The human and canine sequences differed in the location of Y-position proline residues and the presence of two unique canine cyanogen bromide peptides, alpha2 CB3b and alpha2 CB3c,5. Knowledge of the conserved and unique features of canine COL1A2 will be valuable for analysis of the expression, synthesis, and structure of type I collagen as well as studies of canine osteogenesis imperfecta.
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PMID:Sequence of canine COL1A2 cDNA: nucleotide substitutions affecting the cyanogen bromide peptide map of the alpha 2(I) chain. 972 Nov 84

To understand the reparative process of medial collateral ligament (MCL), fibrillar collagen and their relative ratios in healing MCL with anterior cruciate ligament (ACL) reconstruction were analyzed. Skeletally mature New Zealand white rabbits were subjected to a mop-end tear of MCL without repair with ACL reconstruction. Rabbits were killed 6 and 52 weeks after injury. Ligamentous tissues from the injury site and sham controls were soaked in 0.5 M acetic acid for 24 h, minced, and treated with pepsin to solubilize collagen. Pepsin solubilized about 80% of the total collagen as determined by hydroxyproline analysis of the pepsin residues. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the solubilized collagen revealed presence of fibrillar collagen types I, III, and V. Densitometric scanning of the protein bands corresponding to types I, III, and V collagen indicated that in sham controls types III and V collagen represented about 8% and 12%, respectively, of the type I collagen whereas the healed MCL ligaments at 6 weeks showed significant increase in type III and V collagen to about 19% and 24%, respectively. By 52 weeks type III collagen in the healed MCL had returned to that of sham controls while type V collagen remained elevated at approximately 18%. These data suggest that presence of type V collagen in high concentration in healing ligaments may have an influence on collagen fibril diameters seen in healed ligament and should be included in the analysis when evaluating ligament healing.
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PMID:Type V collagen is increased during rabbit medial collateral ligament healing. 1106 Dec 96

The sequence of canine COL1A1 cDNA was determined from four overlapping COL1A1 RT-PCR products generated from canine fibroblast RNA. In the translated region, nucleotide identity between canine and human COL1A1 cDNA was 93.2%, although the canine sequence lacked nucleotides 204 to 215 in the region coding for the N-propeptide. Amino acid identity was 97.7%. Total RNA and type I collagen were collected from cultured skin fibroblasts of a 12-week-old male golden retriever with pathologic fractures suggestive of osteogenesis imperfecta (OI) and dentinogenesis imperfecta. Sequential, overlapping approximately 1,000-bp fragments of COL1A1 and COL1A2 cDNA were each amplified by RT-PCR using primers containing 5' T7 polymerase sites. These PCR products were transcribed with T7 RNA polymerase, hybridized into RNA duplexes, and cleaved at mismatch sites with RNase. The proband had an unique cleavage pattern for the fragment of COL1A1 mRNA spanning nucleotides 709 to 1,531. Sequence analysis identified a G to C point mutation for nucleotide 1,276, predicting a codon change from glycine (GGA) to alanine (GCA) for amino acid 208. This change disrupts the normal Gly-X-Y pattern of the collagen triple helix. Restriction enzyme digestion of the RT-PCR product was consistent with a heterozygous COL1A1 mutation. Type I collagen was labeled with 3H-proline, salt precipitated, and analyzed by SDS-PAGE. Pepsin digested alpha chains were over-hydroxylated, and procollagen processing was delayed. Thus, canine and human OI appear homologous in terms of clinical presentation, etiology, and pathogenesis.
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PMID:Sequence of normal canine COL1A1 cDNA and identification of a heterozygous alpha1(I) collagen Gly208Ala mutation in a severe case of canine osteogenesis imperfecta. 1114 34

Osteoarthritis (OA) is a disorder which results in the destruction of the articular cartilage and the remodeling of the subchondral bone in synovial joints. We have analyzed the cartilage collagen from normal and osteoarthritic free-ranging rhesus monkeys from the Cayo Santiago colony. The cartilage samples were assigned a severity score based on histological staging system and were divided into four groups (normals, mild OA, moderate OA and severe OA). After a 4.0 M guanidinium chloride (GuCl) extraction, the remainder of the cartilage was digested with pepsin and the collagen was salt precipitated at 2.5 M and 4.3 M NaCl. The GuCl solubility of the osteoarthritic cartilage increased compared to normals. Collagen extractability by GuCl also increased with the severity of disease. Pepsin digestion followed by salt precipitation shows that collagen from rhesus osteoarthritis cartilage is more easily extracted than from normal cartilage. With an anti-type I collagen antibody we have detected the presence of type I collagen in the severe OA cartilage samples but not in the milder OA groups or in normal cartilage. Total collagen content decreases with severity of OA, which is not due to changes in propyl hydroxylation because examination of collagen hydroxylation, based on hydroxyproline analysis, shows no difference between OA and normal cartilage.
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PMID:Analysis of collagens solubilized from cartilage of normal and spontaneously osteoarthritic rhesus monkeys. 1155 Jul 7


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