THE ELASTIC FIBER A REVIEW

1973 ◽  
Vol 21 (3) ◽  
pp. 199-208 ◽  
Author(s):  
RUSSELL ROSS
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Elastic Properties ◽  
Lysyl Oxidase ◽  
Elastic Fiber ◽  
Net Charge ◽  
Amorphous Component ◽  
Cross Links

A number of important questions remain to be answered concerning our understanding of elastic tissues. The size and molecular weight of the elastin precursor remains to be clearly established. The number of proteins involved in the microfibrillar component of the elastic fiber are as yet undetermined, although it would appear that they are glycoproteins that may represent a species of reasonably high molecular weight. Clearly the elastic fiber contains two morphologic components. During morphogenesis, the elastic fiber begins to appear in the form of aggregates of microfibrils that take the shape and direction of the presumptive elastic fiber. With increasing maturity elastin begins to form within the interstices of each bundle of microfibrils. By the time the elastic fiber is fully formed it consists largely of the amorphous component, elastin, surrounded by an envelope of microfibrils with microfibrils embedded within its interstices. It has been suggested that the microfibrils form and take their shape extracellularly under the influence of the cells that have secreted their precursors. After the aggregates of microfibrils have taken their shape Ross and Bornstein (22) have suggested that the elastin may interact ionically with the surface of the microfibrils, since each of these two components has an opposite net charge, and may be held in position while desmosine cross-links are established through the action of the enzyme, lysyl oxidase. Thus the microfibrils would serve as a scaffolding to determine morphogenetically the shape and direction to be later taken by the mature elastic fiber. The reason for the elastic properties of the elastin is still yet poorly understood, and the means by which the cells synthesize and secrete both of these components remain to be investigated.

Relation between Molecular Weights and Physical Properties of Rubber Fractions

1941 ◽  
Vol 14 (3) ◽  
pp. 580-589 ◽  
Author(s):  
G. Gee ◽  
L. R. G. Treloar
Keyword(s):  
Molecular Weight ◽  
Natural Rubber ◽  
Physical Properties ◽  
High Molecular Weight ◽  
Elastic Properties ◽  
Elastic Material ◽  
Experimental Results ◽  
Molecular Weights ◽  
High Elasticity ◽  
Latex Rubber

Abstract As high elasticity is a property possessed only by substances of high molecular weight, it is of interest to enquire into the relation between the elastic properties of a highly elastic material such as rubber and its molecular weight. An investigation on these lines has been made possible through the work of Bloomfield and Farmer, who have succeeded in separating natural rubber into fractions having different average molecular weights. The more important physical properties of these fractions have been examined with the object of determining which of the properties are dependent on molecular weight and which are not. Fairly extensive observations were made on the fractions from latex rubber referred to as Nos. 2, 3 and 4 by Bloomfield and Farmer, and some less extensive observations were carried out on the less oxygenated portion of fraction No. 1 obtained from crepe rubber (called hereafter 1b) . Before considering these experimental results, and their relation to the molecular weights of the fractions, it will be necessary to refer briefly to the methods used for the molecular-weight determinations, and to discuss the significance of the figures obtained.

scholarly journals Targeted Disruption of Fibulin-4 Abolishes Elastogenesis and Causes Perinatal Lethality in Mice

2006 ◽  
Vol 26 (5) ◽  
pp. 1700-1709 ◽  
Author(s):  
Precious J. McLaughlin ◽  
Qiuyun Chen ◽  
Masahito Horiguchi ◽  
Barry C. Starcher ◽  
J. Brett Stanton ◽  
...  
Keyword(s):  
Lysyl Oxidase ◽  
Elastic Fiber ◽  
Aneurysm Rupture ◽  
Elastic Fibers ◽  
Targeted Disruption ◽  
Descending Aorta ◽  
Extracellular Matrix Molecule ◽  
Cross Links ◽  
Perinatal Lethality ◽  
Severe Lung

ABSTRACT Elastic fibers provide tissues with elasticity which is critical to the function of arteries, lungs, skin, and other dynamic organs. Loss of elasticity is a major contributing factor in aging and diseases. However, the mechanism of elastic fiber development and assembly is poorly understood. Here, we show that lack of fibulin-4, an extracellular matrix molecule, abolishes elastogenesis. fibulin-4 −/− mice generated by gene targeting exhibited severe lung and vascular defects including emphysema, artery tortuosity, irregularity, aneurysm, rupture, and resulting hemorrhages. All the homozygous mice died perinatally. The earliest abnormality noted was a uniformly narrowing of the descending aorta in fibulin-4 −/− embryos at embryonic day 12.5 (E12.5). Aorta tortuosity and irregularity became noticeable at E15.5. Histological analysis demonstrated that fibulin-4 −/− mice do not develop intact elastic fibers but contain irregular elastin aggregates. Electron microscopy revealed that the elastin aggregates are highly unusual in that they contain evenly distributed rod-like filaments, in contrast to the amorphous appearance of normal elastic fibers. Desmosine analysis indicated that elastin cross-links in fibulin-4 −/− tissues were largely diminished. However, expression of tropoelastin or lysyl oxidase mRNA was unaffected in fibulin-4 −/− mice. In addition, fibulin-4 strongly interacts with tropoelastin and colocalizes with elastic fibers in culture. These results demonstrate that fibulin-4 plays an irreplaceable role in elastogenesis.

Do Proline-rich Proteins Modulate a Transglutaminase Catalyzed Mechanism of Candidal Adhesion?

1993 ◽  
Vol 4 (3) ◽  
pp. 293-299 ◽  
Author(s):  
S.D. Bradway ◽  
M.J. Levine
Keyword(s):  
Molecular Weight ◽  
Cell Wall ◽  
High Molecular Weight ◽  
Surface Proteins ◽  
Cross Linking ◽  
Cell Wall Proteins ◽  
Epithelial Surface ◽  
High Molecular Weight Complex ◽  
Sds Page ◽  
Cross Links

Previously, we reported that a membrane-bound epithelial enzyme, transglutaminase (TGase), catalyzes the covalent cross-linking of acidic proline-rich proteins (APRPs) to surface proteins of buccal epithelial cells (BECs). The purpose of this study was twofold: (1) to provide evidence that TGase stabilizes C. albicans adhesion by covalently cross-linking C. albicans and BEC surface proteins and (2) to implicate PRPs in the modulation of this adhesive mechanism. The reactivity of candidal cell wall proteins with TGase was assessed in two separate experiments. Initially, following incubation with native BECs, the cross-linking of iodinated candidal cell wall proteins into high-molecular-weight complexes, as shown by SDS-PAGE/ autoradiography, was inhibited by the TGase inhibitor iodoacetamide. Additionally, [14C]putrescine in the presence of purified TGase, but not [14C]putrescine alone, was shown by SDS-PAGE/fluorography to be cross-linked into surface proteins of both morphogenetic forms (blastospore > hyphal forms) of C. albicans. In adherence assays, a component of both blastospore and hyphal form Candida/BEC adherence was shown to be resistant to detachment by heating adherent cells in 1% SDS at 100°C. However, pretreatment of BECs with iodoacetamide decreased SDS resistant adherence of both forms of C. albicans by =75%. When incubated with [125I]APRPs and purified TGase, both morphogenetic forms of C. albicans bound dramatically more APRP than controls without TGase. [125I]APRP binding in experimental, but not control, samples was resistant to repeated extraction (48 h) with 4% SDS/10% β-mercaptoethanol at 65°C, suggesting that [125I]APRPs were cross-linked to the Candida surface. SDS-PAGE/fluorography was used to verify that APRPs, in Lyticase digests of Candida cell walls, were cross-linked into a high-molecular-weight complex. These experiments suggest that epithelial TGase may stabilize Candida adherence by cross-linking Candida and BEC surface proteins. Additionally, because TGase cross-links APRPs to candidal and epithelial surface proteins, APRPs may interfere with TGase catalyzed mechanisms of adhesion. Supported by USPHS grants DE00185, DE07585, and OSU Seed grant.

scholarly journals Studies on the assembly of the rat lens capsule. Biosynthesis of a cross-linked collagenous component of high molecular weight

1980 ◽  
Vol 190 (2) ◽  
pp. 229-237 ◽  
Author(s):  
J G Heathcote ◽  
A J Bailey ◽  
M E Grant
Keyword(s):  
Molecular Weight ◽  
Tissue Culture ◽  
High Molecular Weight ◽  
Lens Capsule ◽  
Cross Link ◽  
Membrane Matrix ◽  
Cross Links ◽  
High Molecular Weight Aggregate

1. Intact rat lenses in tissue culture synthesize hydroxy[3H]proline-containing polypeptides of apparent mol.wt. approx. 180000, which become assembled into aggregates of higher molecular weight with time. 2. Both the 180000-mol.wt. species and the aggregates are components of the deoxycholate-insoluble base-membrane matrix. 3. Formation of the high-molecular-weight aggregate is accompanied by the biosynthesis of the reducible hydroxylysine-derived cross-link hydroxylysino-5-oxo-norleucine. 4. Hydroxylysino-5-oxonorleucine and dehydrohydroxylysinonorleucine are the major reducible cross-links present in intact foetal and 1-month-old calf lens capsules.

Comparison of the Cross-Linking Patterns of Lamprey Fibrinogen and Fibrin by the Action of the Intrinsic Lamprey Factor XIII and Human Factor XIII during the Process of Blood Coagulation

1977 ◽  
Vol 38 (02) ◽  
pp. 0429-0437 ◽  
Author(s):  
Patricia A. Murtaugh
Keyword(s):  
Molecular Weight ◽  
Blood Coagulation ◽  
High Molecular Weight ◽  
Factor Xiii ◽  
Human Factor ◽  
Cross Linking ◽  
High Molecular Weight Polymer ◽  
Cross Links ◽  
Α Chain ◽  
A Chain

SummaryIntrinsic lamprey factor XIII cross-links the γ-chain of lamprey fibrin (50,000 daltons) to the γ-dimer (100,000 daltons). The a-chain (110,000 daltons) is cross-linked very slowly to a-dimer (210,000 daltons) and a-trimer (330,000 daltons). In contrast, human factor XIII, when added in combination with intrinsic lamprey factor XIII, cross-finks the a-chain of lamprey fibrin to a high molecular weight polymer, and any remaining γ-chain is also cross-linked to a polymer. However, the γ-chain that has previously cross-linked to the γ-dimer by the intrinsic lamprey factor XIII remains as a γ-dimer. Factor XIII-free lamprey fibrin cross-links all its subunits (α, β, γ) to high molecular weight polymers when human factor XIII is added. In contrast to human and bovine fibrin where α-chain cross-linking in the process of blood coagulation commences when all of the γ-chain has cross-linked, the lamprey α-chain will begin to cross-link when approximately half of the γ-chain has cross-linked to the γ-dimer.

Microtubule motors and other maps

1990 ◽  
Vol 48 (3) ◽  
pp. 1-1
Author(s):  
Richard B. Vallee
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cytoplasmic Dynein ◽  
Organelle Transport ◽  
Structural Components ◽  
Microtubule Associated Proteins ◽  
Microtubule Motors ◽  
Associated Proteins ◽  
The Subject ◽  
Intracellular Motility

Microtubules are involved in a number of forms of intracellular motility, including mitosis and bidirectional organelle transport. Purified microtubules from brain and other sources contain tubulin and a diversity of microtubule associated proteins (MAPs). Some of the high molecular weight MAPs - MAP 1A, 1B, 2A, and 2B - are long, fibrous molecules that serve as structural components of the cytamatrix. Three MAPs have recently been identified that show microtubule activated ATPase activity and produce force in association with microtubules. These proteins - kinesin, cytoplasmic dynein, and dynamin - are referred to as cytoplasmic motors. The latter two will be the subject of this talk.Cytoplasmic dynein was first identified as one of the high molecular weight brain MAPs, MAP 1C. It was determined to be structurally equivalent to ciliary and flagellar dynein, and to produce force toward the minus ends of microtubules, opposite to kinesin.

Studies on the Functionality of Newly Synthesized Fibrinogen after Treatment of Acute Myocardial Infarction with Streptokinase, Increase in the Rate of Fibrinopeptide Release

1993 ◽  
Vol 70 (06) ◽  
pp. 0978-0983 ◽  
Author(s):  
Edelmiro Regano ◽  
Virtudes Vila ◽  
Justo Aznar ◽  
Victoria Lacueva ◽  
Vicenta Martinez ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Molecular Weight ◽  
Steady State ◽  
High Molecular Weight ◽  
Coronary Arteries ◽  
Risk Index ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Fibrinopeptide A

SummaryIn 15 patients with acute myocardial infarction who received 1,500,000 U of streptokinase, the gradual appearance of newly synthesized fibrinogen and the fibrinopeptide release during the first 35 h after SK treatment were evaluated. At 5 h the fibrinogen circulating in plasma was observed as the high molecular weight fraction (HMW-Fg). The concentration of HMW-Fg increased continuously, and at 20 h reached values higher than those obtained from normal plasma. HMW-Fg represented about 95% of the total fibrinogen during the first 35 h. The degree of phosphorylation of patient fibrinogen increased from 30% before treatment to 65% during the first 5 h, and then slowly declined to 50% at 35 h.The early rates of fibrinopeptide A (FPA) and phosphorylated fibrinopeptide A (FPAp) release are higher in patient fibrinogen than in isolated normal HMW-Fg and normal fibrinogen after thrombin addition. The early rate of fibrinopeptide B (FPB) release is the same for the three fibrinogen groups. However, the late rate of FPB release is higher in patient fibrinogen than in normal HMW-Fg and normal fibrinogen. Therefore, the newly synthesized fibrinogen clots faster than fibrinogen in the normal steady state.In two of the 15 patients who had occluded coronary arteries after SK treatment the HMW-Fg and FPAp levels increased as compared with the 13 patients who had patent coronary arteries.These results provide some support for the idea that an increased synthesis of fibrinogen in circulation may result in a procoagulant tendency. If this is so, the HMW-Fg and FPAp content may serve as a risk index for thrombosis.

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