02087nas a2200265   4500008004100000022001400041245015000055210006900205260009900274300001400373490000700387520109300394653002201487653001401509653001601523653003701539653001101576653000901587100001401596700001701610700002401627700002101651700001801672856013101690       2009                        eng d  a0142-961200aOn the change in bacterial size and magnetosome features for magnetospirillum magnetotacticum (MS-1) under high concentrations of zinc and nickel0 achange in bacterial size and magnetosome features for magnetospi  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcSEP  a4211-42180 v303 a<p>The characteristic size, shape and specific alignment of magnetite crystals synthesized by magnetotactic bacteria is a highly coordinated process with precise control over magnetosome vesicle formation, uptake and transport of Fe, and magnetite biomineralization. Magnetosome membranes along with some specific membrane proteins regulate crystal nucleation and morphology of magnetite. Several previous works have indicated that the morphology of mature magnetite crystals is largely unaffected by environmental conditions, though some recent studies have shown the possibility of manipulation of the biomineralization process. In this study we have examined the effects of high concentrations of Zinc and Nickel on the growth of Magnetospirillum magnetotacticum (MS-1) and the corresponding magnetosome formation. Using various characterizations it is shown that the growth of the bacterial cells, as well as the size, shape and magnetosome chain alignment is significantly influenced in the presence of high concentrations of Zn or Ni. (C) 2009 Elsevier Ltd. All rights reserved.</p>10aBiomineralization10amagnetite10aMagnetosome10aMagnetospirillum magnetotacticum10aNickel10azinc1 aKundu, S.1 aKale, A., A.1 aBanpurkar, Arun, G.1 aKulkarni, G., R.1 aOgale, S., B.  uhttp://library.ncl.res.in/content/change-bacterial-size-and-magnetosome-features-magnetospirillum-magnetotacticum-ms-1-under-002192nas a2200253   4500008004100000022001400041245016500055210006900220260000800289300001400297490000700311520130700318653002201625653001201647653002401659653001301683653001801696100002001714700001601734700002001750700001801770700002201788856012801810       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  uhttp://library.ncl.res.in/content/synthesis-phospho-polypeptides-phosphate-containing-n-carboxyanhydride-application-enzyme