01757nas a2200241   4500008004100000022001400041245008700055210006900142260007100211300001400282490000600296520090500302653002501207653002301232653002901255653001301284653001701297100002101314700001801335700002201353700002201375856011801397       2014                        eng d  a2168-048500aInvestigation of C-C bond formation mediated by bombyx mori silk fibroin materials0 aInvestigation of CC bond formation mediated by bombyx mori silk   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN  a1510-15170 v23 a<p>The formation of C-C bonds is a prerequisite for all life on earth. Understanding the role of proteins in mediating the formation of these bonds is important for understanding biological mechanisms in evolution, as well as for designing ``green catalysts''. In this work, the ability of silk fibroin (SF) proteins to mediate selective C-C bond formation under mild conditions was comprehensively evaluated and compared between different SF-based materials and other proteins. Aqueous SF solution (ASFS), freeze-dried SF (FDSF), mesoporous SF (MPSF), and SF hydrogel (SFHG) materials were prepared and characterized by a variety of techniques including, among others, FE-SEM, ICP-OES, FT-IR, and TGA. The nitroaldol (Henry) reaction, Knoevenagel condensation, and direct aldol reaction were used as models for this study, in which the recovery and reusability of the protein was also evaluated.</p>10aAldol-like reactions10aC-C Bond formation10aKnoevenagel condensation10aProteins10aSilk fibroin1 aKuehbeck, Dennis1 aGhosh, Munmun1 aGupta, Sayam, Sen1 aDiaz, David, Diaz  uhttps://library.ncl.res.in/content/investigation-c-c-bond-formation-mediated-bombyx-mori-silk-fibroin-materials-002193nas a2200253   4500008004100000022001400041245016500055210006900220260000800289300001400297490000700311520130700318653002201625653001201647653002401659653001301683653001801696100002001714700001601734700002001750700001801770700002201788856012901810       2020                        eng d  a2192-650600aSynthesis of phospho-polypeptides via phosphate-containing N-carboxyanhydride: application in enzyme-induced self-assembly, and calcium carbonate mineralization0 aSynthesis of phosphopolypeptides via phosphatecontaining Ncarbox  cMAY  a1053-10640 v853 a<p>An easy synthetic strategy was developed to synthesize the phosphate-functionalized amino acid N-carboxyanhydride (NCA), using simple primary amine initiators to obtain homo and block phospho-polypeptides with controlled molecular weight and molecular weight distribution. The methodology was extended to the synthesis of the end-functionalized homo polypeptides (15 to 50 repeat unit) and block co-polypeptides with PEG (0.7 K, 2 K, and 5 K) and glycopolypeptide (15-unit mannose glycopolypeptide) as one of the blocks. The deprotected fully water-soluble anionic phosphate-based polypeptides showed pH-dependent helical conformation with a helical content of 20 %, which further changed to beta-sheets upon addition of the enzyme alkaline phosphatase (ALP) due to dephosphorylation. The block co-polypeptide containing PEG as one of the blocks led to its self-assembly into colloidal structures, such as vesicles with a hydrodynamic diameter of similar to 250 nm, due to the formation of amphiphilic block co-polymer upon dephosphorylation. The nature of the colloidal structures formed can be temporally controlled by the extent of dephosphorylation. Finally, the phospho-polypeptides serve as a template for the mineralization of calcium carbonate with varying polymorphs and morphologies.</p>
10aBiomineralization10aenzymes10aphosphopolypeptides10aProteins10aSelf-assembly1 aMondal, Basudeb1 aDas, Soumen1 aPanda, Sidharth1 aDutta, Tahiti1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/synthesis-phospho-polypeptides-phosphate-containing-n-carboxyanhydride-application-enzyme