The effects of 60 organic solvent on poly(lactic acid) (PLA) were systematically investigated using the Hansen solubility parameter (HSP). The hydrogen bonding solubility parameter accurately reflects the solubility of PLA films using HSP but it depends on hydrogen bonding, as well as dispersion and polar parameters. The PLA films immersed in organic solvent became cloudy and showed no changes in chemical structure. However, solvent‐induced crystallization of the PLA films was observed. Crystalline structures do not dependent on the organic solvent but on the degree of swelling. The organic solvent‐induced crystallization formed a crystallized mixture of a‐ and β‐forms. The density of the crystalline PLA films was lower than that of amorphous PLA films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

HSP47 is a collagen-specific molecular chaperone that specifically recognizes and binds to the triple helical domain of various types of collagens. Here we report the cloning of the entire coding region of a novel collagenlike protein by yeast two-hybrid screening of a 17.5-day whole mouse embryo cDNA library using HSP47 as a bait. The cDNA of this protein and its deduced amino acid sequence are 2,690 bp and 438 amino acids long, respectively. The protein contains two clusters of Gly-X-Y collagenous repeats and three noncollagenous domains. Northern blot analysis showed that its mRNA is specifically expressed in the testis and ovary in adult tissues and that expression in these tissues is highest in the neonate. Biochemical characterization of this protein revealed that its proline residues are hydroxylated, it undergoes N-linked glycosylation, it forms trimers, and it is secreted in vitro. Immunohistochemical studies showed that the myoid cells and the pre-theca cells synthesized it in the testis and ovary, respectively, resulting in the accumulation of this protein in the extracellular spaces of these organs. These observations suggest that this protein is a new member of the collagen protein family. We thus designated this protein as type XXVI collagen.Collagen is the most abundant protein in vertebrates. It is a major component of the extracellular matrix, which consists of specialized fibrils and networks around cells and in the interstitial spaces between the cells. Twenty-five types of collagen have now been identified (1-5). During the development of mammals, these collagens are expressed in various spatiotemporal patterns. The fibril-forming collagens are the most abundant of the collagens and include types I, II, and III (6). Other collagens known as the FACIT collagens (Fibril-associated Collagens with Interrupted Triple Helices), which include types IX, XII, XIV, XVI, and XIX, associate with the surface of the collagen fibrils and modify their interactive properties (7-9). In addition, nonfibrillar collagens, which include types XIII, XVII, and XXV, are reported to have transmembrane domains and appear to localize at the cell surface (5, 10, 11).Despite the differences among the collagens, all share in common a triple helical structure composed of three polypeptides consisting of Gly-X-Y repeats, where X is any amino acid, and Y is frequently proline or hydroxyproline. Each chain is a left-handed helix, and the three chains wind around each other in a right-handed superhelix (1, 6).The procollagens are synthesized in and cotranslationally transported into the endoplasmic reticulum (ER).1 After translation is completed, the procollagens form a trimer at the C terminus. Only properly folded triple helical forms of procollagens are secreted by the cells. During collagen biosynthesis, the nascent procollagen chain is modified by unique enzymes that include prolyl-4 hydroxylase, which stabilize the triple helical structure. After being secreted by the cell, the N-and C-propeptides are cleaved by specific ...

Ovomucin-protein conjugates were prepared to develop a new kind of functional glycoprotein-protein conjugates. Soluble reduced ovomucin was self-associated by transglutaminase and the reactant had better foaming and emulsifying properties than untreated ovomucin. The conjugation of ovomucin with casein or soy protein was also attempted by transglutaminase.Ovomucin-llS globulin and ovomucin-asl-casein conjugates were formed by cross-linking between ovomucinand IIS globulin or asl-casein. Themolecular weight of these conjugates were larger than that of ovomucin self-associated with transglutaminase. Ovomucin-l lS globulin conjugate showed marked increases in the foaming properties, because of the high molecular weight of the conjugate. On the other hand, ovomucin-asl-casein conjugate had significant increases in the emulsifying properties, probably due to the increase in the h\drophobic(asl -casein)-hydrophilic(ovomucin) balance.Recently, protein-macromolecule conjugates,

The effects of methanol and ethanol vapor-induced crystallization on vapor and gas permeabilities and on the structure of poly(lactic acid) (PLA) films were systematically investigated. At high temperature conditions, the vapor permeability of PLA films decreased with increasing exposure time. The PLA films that were exposed to alcohol vapor became slightly cloudy, and no changes in chemical structure were observed. Alcohol vapor-induced crystallization formed a-crystal structure. The vapor permeability decreased with increasing crystallinity. However, nitrogen permeability slightly increased after vapor-induced crystallization. The dependence of crystallinity on vapor and gas permeabilities was different from each penetrant. Total crystalline structures, including continuous crystal structures, remaining amorphous regions, and their interface depend on vapor and gas permeabilities. V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40140.

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