Showing papers on "Gelatin published in 1974"

Cathepsin B1. A lysosomal enzyme that degrades native collagen

Abstract: 1. Experiments were made to determine whether the purified lysosomal proteinases, cathepsins B1 and D, degrade acid-soluble collagen in solution, reconstituted collagen fibrils, insoluble collagen or gelatin. 2. At acid pH values cathepsin B1 released 14C-labelled peptides from collagen fibrils reconstituted at neutral pH from soluble collagen. The purified enzyme required activation by cysteine and EDTA and was inhibited by 4-chloromercuribenzoate, by the chloromethyl ketones derived from tosyl-lysine and acetyltetra-alanine and by human α2-macroglobulin. 3. Cathepsin B1 degraded collagen in solution, the pH optimum being pH4.5–5.0. The initial action was cleavage of the non-helical region containing the cross-link; this was seen as a decrease in viscosity with no change in optical rotation. The enzyme also attacked the helical region of collagen by a mechanism different from that of mammalian neutral collagenase. No discrete intermediate products of a specific size were observed in segment-long-spacing crystalloids (measured as native collagen molecules aligned with N-termini together along the long axis) or as separate peaks on gel filtration chromatography. This suggests that once an α-chain was attacked it was rapidly degraded to low-molecular-weight peptides. 4. Cathepsin B1 degraded insoluble collagen with a pH optimum below 4; this value is lower than that found for the soluble substrate, and a possible explanation is given. 5. The lysosomal carboxyl proteinase, cathepsin D, had no action on collagen or gelatin at pH3.0. Neither cathepsin B1 nor D cleaved Pz-Pro-Leu-Gly-Pro-d-Arg. 6. Cathepsin B1 activity was shown to be essential for the degradation of collagen by lysosomal extracts. 7. Cathepsin B1 may provide an alternative route for collagen breakdown in physiological and pathological situations.

Studies of the collagen fold formation and gelation in solutions of a monodisperse alpha gelatin.

Abstract: The reversion of a monodisperse α gelatin to the collagen fold over a concentration range up to 5 % w/v has been studied by n.m.r., dielectric relaxation, differential scanning calorimetry, optical rotation, viscometry and light scattering techniques. The folding process is shown to be intramolecular and the minimum concentration for gelling is correctly predicted from the behaviour of less concentrated solutions.

Phasenzustand, Struktur und mechanische Eigenschaften des gelartigen Systems Wasser ‐ Gelatine ‐ Dextran

Abstract: State of Phase, Structure and Mechanical Properties of the Gelatinous System Water-Gelatin-Dextran. Increasing use of water-protein-polysaccharide systems as plasma replacing liquids and synthetical food has led to an examination of the thermodynamic compatibility of polymers in an aqueous medium. In the examination of the state of phase of the system water-gelatin-dextran self-association of gelatin was shown to be the main reason for its incompatibility with dextran. At low dextran concentrations the gelatinous system is monophasic but it proceeds to a two-phase state at higher concentration of dextran. The monophasic system shows lower, the two-phase system a higher flexibility than the gelatin-gel of the same concentration.

Gastric juice resistant gelatin capsules and a process for the production thereof

Abstract: Gastric juice resistant gelatin capsules characterized by a gastric juice resistant outer coating of an anionic polymerizate of methacrylic acid and acrylic acid esters and an intermediate layer between the outer layer and the gelatin shell of a cationic polymerizate of di-lower alkylamino lower alkylmethyl acrylate with other neutral methacrylic esters and a process for preparing the same.

Electrochemical deposition of bone

Abstract: A method of improving orthopedic implant materials by the simultaneous electrodeposition of bone and collagen onto a prosthesis is provided. Collagen fibrils are dispensed in a gelatin medium and the gelled collagen is dissolved in a water-glycerine solution. Finely divided bone particles are then added to this solution and, by applying a voltage to a pair of electrodes immersed in the solution, adherent bone and collagen coatings of preferably 1-5 mils thickness are formed on the cathodic electrode.

Microcapsule having hydrophilic wall material and containing water soluble core material

Abstract: A pressure-rupturable, liquid-droplet-containing microcapsule having walls of hydrophilic polymeric film-material such as gelatin wherein the liquid core-material is a water-immiscible oil having water dissolved therein together with additional material which is water-soluble such as a water-soluble colorless chromogenic dye-precursor material or color-developing reactant material.

An Ellipsometric Study of the Adsorption of Gelatin on Silver Bromide

Abstract: Optically-polished surfaces of silver bromide were examined by ellipsometry to establish their optical properties. The adsorption of gelatin onto the surfaces from an aqueous solution at 40° C was then followed ellipsometrically. Measurements were carried out as a function of time and as a function of pH at pBr 3. From the measurements, it was possible to obtain the adsorption excess of the gelatin at the surface, the optical thickness of the adsorbed layer and the concentration of gelatin in the adsorbed layer. The optical thickness of the adsorbed layer was found to vary significantly with pH and to reach a maximum value of ca. 400 A at the isoelectric point of the gelatin.

Effects of water on the mechanical properties of gelatin films.

Abstract: The mechanical properties of gelatin films were studied in relation to the effect of water, and compared with those of collagen films. The S-shaped sorption isotherm was separated into an adsorption curve C1 and dissolution curve C2. From the C2 curve, the interaction parameter χ1 of Flory–Huggins' equation was calculated. The χ1 of gelatin were larger than those of collagen at low relative humidities (RH), while they coincided with each other at high RH. It was found that a composite curve was made by shifting stress relaxation curves obtained at different humidities along the log time axis. The shift factor for the formation of the composite curve was analyzed by Fujita–Kishimoto's equation, which was based on the free volume theory. The parameter β, which expressed the extent of the contribution of sorbed water to the increase in the free volume of the system, was 0.05 in the range of C2 from 0 to 0.08 (0–65% RH). This value was much smaller than 0.16 for collagen. The value was 0.16 in the range of C2 higher than 0.08, which was equal to that of the collagen. Dynamic shear modulus G′, loss modulus G″, and tan δ were determined as functions of RH. The gelatin film extended more than 100% at 73% RH under the very small stress of about 107 dyn/cm2. This corresponds to the region where β changes from 0.05 to 0.16, although such a phenomenon was not observed in the collagen film. The wide-angle X-ray pattern of extended gelatin was similar to that of renatured collagen fiber.

Gelatin-encapsulated digoxin solutions and method of preparing the same

Abstract: Digoxin solutions are disclosed which are compatible with gelatin and which are of relatively high concentration, thereby permitting encapsulation of therapeutic amounts of digoxin in soft gelatin capsules of moderate size. The digoxin is first micronized and then dissolved in a vehicle consisting predominately of polyethylene glycol having a molecular weight no greater than about one thousand and having a melting temperature no greater than about 35° C., to provide a digoxin concentration of at least one-half milligram per milliliter and preferably one milligram per milliliter. Solutions composed of various solvent blends are disclosed, including solutions which are highly viscous (semi-solid) at room temperature.

The isolation of two types of collagen from embryonic bovine epiphyseal cartilage.

Abstract: The nature of the collagen in embryonic and postnatal bovine epiphyseal cartilage was studied by amino acid analysis, extraction in denaturants, and extraction in denaturants after prior digestion of the cartilage with pepsin. Components of both Type I collagen and Type II collagen were isolated by molecular sieve filtration from the gelatin extracted from 4–5 month old embryonic bovine epiphyseal cartilage, and characterized by their behavior during ion exchange chromatography, amino acid composition and their content of hydroxylysine and glycosydically substituted hydroxylysine residues. Type I collagen accounted for about one-third of the total collagen content of epiphyseal cartilage. It was preferentially extracted in denaturant salts, whilst Type II collagen, essentially insoluble in denaturants, could be extracted from the cartilage only after prior digestion of the cartilage with pepsin. The marked preponderance of α components compared with higher molecular weight polymers in the extracted Type I gelatin suggested a paucity of intramolecular crosslinkages, and the lability of the intermolecular crosslinks to denaturants at neutral pH, suggests that the intermolecular, aldehyde-derived crosslinks of Type, I collagen in cartilage are similar to those in the Type I collagen of bone rather than those present in the Type I collagen of skin and other non-mineralized connective tissues. The marked differences in the solubility properties of Type I and Type II collagens of cartilage suggests that the stability and possibly the chemical nature of the intermolecular crosslinkages in Type II collagen, as well as the number of intramolecular crosslinkages, differs in the two types of collagen present in cartilage.

Process for hardening gelatin in photographic layers which contain a thickener and hardener by utilizing acrylic acid-acrylamide copolymers

Abstract: A process for hardening gelatin which comprises incorporating an acrylic acid-acrylamide copolymer into a system containing gelatin, a thickener and a hardener. Hardened gelatin layers having sufficiently high melting temperatures and high swelling can be obtained, which are useful as photographic layers.

Fortified gelating dessert powder and process

Abstract: A method for producing fruit-flavored gelatin dessert compositions containing both adipic and fumaric acids and which are fortified with vitamin A, vitamin C and iron has been developed. Vitamin C, which may be coated with a gum, is dry-blended with a vitamin A/iron/sucrose mixture. The gelatin is combined with fumaric acid prior to being blended with the fortifying ingredients and other mix components.

The Structure of Gelatin Crosslinked with Formaldehyde

Abstract: Crosslinking a gelatin layer with formaldehyde gives a decrease in swelling and solubility as function of the reaction time and the pH value. The molecular weight distribution of the crosslinked ge...

Interaction of gelatin with stereospecific binding proteins and its enhancement of competitive binding assays.

Abstract: The effect of gelatin (0·5 g/l) on binding curves at high dilution of three classes of stereo-specific binding proteins was studied. These included two antibodies (to oestradiol and aldosterone), six transins (horse and dog transcortins, human thyroxine-binding globulin, human sex steroid-binding globulin, and guinea pig transprogestin), and one receptor (bovine adrenal protein kinase). Gelatin increased the apparent binding of all these proteins, particularly at the highest dilutions and sometimes in a striking manner. While much of this action can be attributed to its decreasing the adhesion of the dilute binding protein to glass, gelatin also increased the apparent uptake of some tracers by certain adsorbents. Similar findings were obtained using human gamma globulin (2 g/l). These effects resulted in increased sensitivity and improved reproducibility in the assays employing them.

Method for hardening gelatin

Abstract: This invention relates to a method of hardening gelatin which is accomplished by combining a compound containing at least one carbo-di-imide group with a compound having at least two vinyl sulfonyl groups. This combination has application to the photographic industry by providing a method of hardening the type of gelatin which is used in a gelatin -- containing photographic layer of a light-sensitive halide photographic material.

Coated synthetic film materials

Abstract: Improving the adhesion of a gelatin coating to a styrene homopolymer or copolymer film by solvent treating and corona discharge treating the film prior to coating with a gelatin layer in the production of a coated photobase.

The dissolution of bovine and chicken bone collagens in concentrated formic acid

Abstract: Bovine and chicken bone collagens have been solubilized and presumably denatured (gelatin) by treatment of demineralized, powdered tissue with 70% formic acid. Short periods of extraction such as four hours at 30°, conditions commonly used during cyanogen bromide cleavage of collagen, solubilized 50% and 15% of the chicken and bovine bone collagens respectively. Treatment of the tissues with sodium borohydride partially inhibited the extraction of collagen from chicken bone, but had little effect on the extraction of calf bone collagen. The heterogeneity of the bone gelatin from both species on disc electrophoretic analysis suggested that peptide bonds had been cleaved in some of the collagen chains during exposure to formic acid, thus facilitating the solubilization of the bone collagen as the gelatin. Analysis of the collagen extracted from chicken bone for reducible crosslinks indicated that a large proportion of these bonds had remained intact, in contrast to a previous finding that most of these crosslinks were destroyed in bone gelatin extracted by 4 M CaCl2, at pH 7.0. The stability of the major reducible crosslinks in bone collagen to severe acid conditions may explain in part some of its unique properties, such as its failure to swell or be solubilized in dilute acid, which distinguish it from soft tissue collagens.

Wipe on color proofing process and product

Abstract: A process of color proofing by a wipe on method and color proof product produced thereby wherein the color proof process comprises coating at least one side of a paper with a bichromate gelatin emulsion and thereafter drying the same; exposing the emulsion through a color separation negative so as to expose a portion of the gelatin and effect hardening of the exposed gelatin; applying a first desired color, i.e., pigment formulation, to the gelatin emulsion; washing the coated paper to remove the unhardened gelatin and thereafter drying the same; coating the paper again with the bichromate gelatin emulsion, drying the same and exposing this further emulsion through a second color separation negative so as to again cause the exposed gelatin to harden; applying a second desired color to the gelatin and drying the coated paper and finally washing the coated paper to remove the unhardened gelatin with subsequent drying. The steps of applying the bichromate gelatin emulsion, exposing the emulsion through a color separation negative, applying a desired color and washing the paper to remove unhardened gelatin can be repeated for as many colors as desired. One or both sides of the paper can be advantageously processed in the above manner to provide a color proof substantially indistinguishable from the actual copies made with subsequently produced printing plates. Additional variations of the above process are applicable including exposing the emulsion through more than one separation negative at a time with overprinting if desired.

o-Phthaldialdehyde reactive substances in dog's plasma and gelatin (Haemaccel) complicating the determination of histamine.

Abstract: These results indicate that even small alterations of the incubation procedure witho-phthaldialdehyde may considerably influence the specificity of the fluorometric histamine assay Tests for identification of this amine are always necessary in studies on histamine in body fluids or following the administration of drugs

Encapsulation of Spherical Particles as a Characteristic of Gelatin Fractions

Abstract: Both ethanol (1–4, 8, 9) and detergent-gelatin (4, 10) fractionation procedures have been reported in the literature. For this work, gelatin has been fractionated by using the coacervation process with acetone being used as coacervating agent.

Color photographic material comprising acid-treated gelatin

Abstract: Acid-treated gelatin having a jelly strength of at least 250 g (in bloom) is added to silver halide emulsion layers, ultraviolet absorber layer, etc. which are coated on a resin coated paper and which contain high boiling point solvent, whereby deterioration of physical properties of surface of the photographic paper can be prevented.

The Kinetics of the Development of Rigidity in Gelatin Gels

Abstract: The kinetics of the development of the rigidity of gelatin gels, at con tant temperature, indicatcs second-order concentration dependence of the rate of increase of rigidity in the early stages of gel formation. At the gelation point, the value of (dGdt)t→0 has a higher order concentration dependence, approaching third-order. During later stages of the gel maturation period the kinetics reduce to tho e satisfying the equation for a first-order reaction. The mechanisms involved are discussed in terms of nucleation, inter-chain linkages and continued chain folding in cross-linked segments.

Novel polymeric derivatives of tetrazole-5-thiols and their metal and ammonium salts

Abstract: Novel polymeric derivatives of tetrazole-5-thiols and their metal and ammonium salts, and the preparation of such compounds which are useful as gelatin thickeners or in their production, are disclosed.

Method of producing a hardened gelatin layer using aqueous solution of a 2-halogeno pyridinium compound

Abstract: This invention relates to the hardening of gelatin layers. The gelatin is heated with an aqueous solution of a 2-halogeno pyridinium compound.

Effect of low molecular weight materials on physical and mechanical properties of gelatin films

Abstract: A study was made of low molecular weight substances on the heat stability, thermal contraction and mechanical properties of gelatin films. It was shown that the heat stability of gelatin decreases considerably on adding compounds containing more than two polar groups and which have no marked effect on the helical structure of gelatin. For materials, which hinder spiralling in gelatin macromolecules during film formation it is not the temperature but super-contraction which decreases. It was found that the effect of low molecular weight substances on thermal contraction of gelatin films (at 20 to 120°), is correlated with their effect on the temperature variation of super-contraction of gelatin. Materials which reduce the thermal contraction of gelatin films normally reduce heat stability. Mechanical properties of gelatin films depend on the structural ordering and moisture content of gelatin. Materials which reduce the spiralling of gelatin macromolecules, or lower the moisture content of the gelatin system increase the brittleness of gelatin films. The elastic properties of films increase if materials introduced enable the moisture content of films to be increased considerably without altering the structure of gelatin.