Dielectric and pyroelectric characterization of anionic and native collagen

1996 ◽  
Vol 36 (24) ◽  
pp. 2932-2938 ◽  
Author(s):  
Ana Maria De Guzzi Plepis ◽  
Gilberto Goissis ◽  
Dilip K. Das-Gupta
Keyword(s):  

1973 ◽  
Vol 133 (4) ◽  
pp. 615-622 ◽  
Author(s):  
Kalindi Deshmukh ◽  
Marcel E. Nimni

Significant amounts of native collagen can be extracted from bovine articular cartilage after removal of the acid mucopolysaccharides by controlled proteolysis. The fraction thus solubilized upon denaturation gives rise to three identical α chains. Cleavage of these chains with CNBr generated nine peptides, all of which contain glycine as one-third of their total amino acid residues. Two of the smaller peptides CB-1 and CB-2 contain partially hydroxylated proline. A similar CNBr digest of intact cartilage also gives a series of peptides identical with those obtained from the soluble cartilage collagen. The absence of cross-linking peptides, the fact that only few β components are seen in articular cartilage collagen and the similarity in peptide pattern between the two collagen fractions investigated, suggests that this collagen is stabilized by a different cross-linking mechanism, possibly involving an association with the tissue proteoglycans.



2019 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Sartika Danial ◽  
Hasnah Natsir ◽  
Seniwati Dali ◽  
Leliani Leliani

Collagenases are enzyme that are able to hydrolyze native collagen into fragment collagen peptides. Collagenases and its hydrolysis products have received tremendous attention in medical and industrial applications. The present study was conducted to isolate and identify new collagenase producing bacteria from fish liquid waste, then produce and characterize collagenase. A total of 7 isolate from fish liquid waste were screened on selective medium containg 2 % collagen and its activity was confirmed by the formation of clear zone. Isolat 6-2 was positif as collagenase producer and identified as Bacillus sp. 6-2 by morphological and biochemical characteristics. The optimum fermentation time of enzyme was investigated. Collagenase crude extract was characterized by the effect of pH, temperature, and metal ions. Isolat 62 optimally produced collagenase enzyme after 30 h of incubation with activity of   0.072 U/mL and protein content of 3.768 mg/mL. The optimum pH and temperature were 7.0 and 40 oC, respectively. The enzyme was activated by 1 mM Ca2+and  Mg2+, and inhibited by   1 mM  Zn2+ and Co2+. Collagenase from Bacillus sp. 6-2 may have potentials for medical and industrial applications.



1954 ◽  
Vol 76 (9) ◽  
pp. 2476-2478 ◽  
Author(s):  
Arthur Veis ◽  
Jerome Cohen
Keyword(s):  


1986 ◽  
Vol 64 (5) ◽  
pp. 387-393 ◽  
Author(s):  
Takuo Nakano ◽  
Paul G. Scott

An endopeptidase which digests denatured collagen to small, dialysable fragments was purified 2675-fold from medium that had been conditioned by the culture of fibroblasts grown from explants of human gingiva. This enzyme was inhibited by chelating agents, but not by phenylmethylsulphonyl fluoride nor by N-ethylmaleimide, and is therefore probably a metalloproteinase. It showed no demonstrable activity against native collagen or ovalbumin, while α-casein was digested slowly, if at all. It therefore belongs to the group of enzymes which have been called tissue gelatinases. This gelatinase was secreted in a latent form or forms and could be activated by proteolysis with trypsin. The active enzyme had an apparent molecular weight of 69 000 (gel chromatography) or 72 000 (gel electrophoresis in sodium dodecyl sulphate) and an apparent isoelectric point of 4.15.



Author(s):  
B. L. Soloff ◽  
T. A. Rado

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.



Author(s):  
W. H. Zucker ◽  
R. G. Mason

Platelet adhesion initiates platelet aggregation and is an important component of the hemostatic process. Since the development of a new form of collagen as a topical hemostatic agent is of both basic and clinical interest, an ultrastructural and hematologic study of the interaction of platelets with the microcrystalline collagen preparation was undertaken.In this study, whole blood anticoagulated with EDTA was used in order to inhibit aggregation and permit study of platelet adhesion to collagen as an isolated event. The microcrystalline collagen was prepared from bovine dermal corium; milling was with sharp blades. The preparation consists of partial hydrochloric acid amine collagen salts and retains much of the fibrillar morphology of native collagen.



Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.



Author(s):  
B. H. Kear ◽  
J. M. Oblak

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.



Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.



Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.



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