A Conformation-dependent Cotton Effect in α-Helical Polypeptides and Proteins<sup>1,2</sup>

Simmons, Norman S.; Cohen, Carolyn; Szent‐Györgyi, Albert; Wetlaufer, Donald B.; Blout, E. R.

doi:10.1021/ja01484a017

Cited by 216 publications

(60 citation statements)

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“…Three of the four samples had residue rotations at 233 m/~ ([ ]23~) lying between -16,000 and -16,900 and one sample had a rotation of --13,700. Other workers have reported values close to either -13,900 (115)(116)(117)(118) or -16,400 (92,119). Similar inconsistencies were encountered by Tomimatsu & Garfield (93) who measured the rotations of two samples of PLGA obtained from the laboratories of Yang and of Blout.…”

Section: Lr'] = A~°~ + A~x~mentioning

confidence: 84%

Physical Chemical Studies on Proteins and Polypeptides

Harrington¹,

Josephs²,

Segal³

1966

Annu. Rev. Biochem.

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Section: Lr'] = A~°~ + A~x~mentioning

confidence: 84%

Physical Chemical Studies on Proteins and Polypeptides

Harrington¹,

Josephs²,

Segal³

1966

Annu. Rev. Biochem.

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“…No correlation between the cell density and 1µ 222 was observed. 1µ 197 , 1µ 208 , and 1µ 217 also show no correlation with the cell density (data not shown), where the intrinsic peaks at 208 and 222 nm are attributed to an ®-helix conformation, the peak at 217 nm is to¯-sheet conformation, and the peak at 197 nm is to random coil conformation in the proteins CD spectra [33][34][35]. These results indicate that the amount of serum proteins adsorbed on the lms does not have a direct in uence on cell growth.…”

Section: Relationship Between Conformation Of Serum Proteins On the Lmentioning

confidence: 99%

Growth of L929 cells on polymeric films prepared by Langmuir–Blodgett and casting methods

Higuchi

Tamiya

Tsubomura

et al. 2000

Journal of Biomaterials Science, Polymer Edition

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The growth and spreading of fibroblast, L929 cells, on various polymeric films prepared by the Langmuir-Blodgett (LB) and casting methods were investigated. L929 cells, which were cultivated on collagen and synthetic polymeric films prepared by the LB method, adhered and spread much more than those on synthetic films prepared by the casting method. This is explained by the fact that cell growth and cell spreading are suitable for L929 cells on the films having serum proteins that contain a high alpha-helix content, because LB films adsorbed those serum proteins estimated from the circular dichroism measurements of the films immersed in cell culture medium. An exponential relationship was observed from the plot of the cell density vs root mean square of roughness of the films, which is estimated by atomic force microscopy, whereas a linear relationship was observed from the plot of the spreading ratio vs the root mean square of roughness. It is suggested that the correlation between the cell growth or spreading ratio and surface roughness of the films where L929 cells were cultivated is considered to be more important than the correlation between the cell growth or spreading ratio and the contact angle of the films.

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“…Measurements were made at 230C in 1-cm quartz cells with a Cary model 60 spectropolarimeter equipped with a model 6001 CD accessory. In ORD studies, the a-helix content was estimated from the mean residue rotation observed at 233 nm by using values of -1800°for 0% a-helix and -12,000°for 100% a-helix, with presumption of linear interpolation (39). Values for bo were also calculated from Moffit plots of Xo = 212 nm and were reduced to a-helix contents by using the formula (bo/-630) X 100% (40).…”

mentioning

confidence: 99%

Ten-nanometer filaments of hamster BHK-21 cells and epidermal keratin filaments have similar structures.

Steinert¹,

Zimmerman²,

Starger³

et al. 1978

Proc. Natl. Acad. Sci. U.S.A.

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The 10-nm filaments of baby hamster kidney (BHK-21) cells, when examined either in the form of native ilanent caps or polymerized in vitro, are long tubes of protein 8-10 nm in diameter. They contain about 42% a-helix, which, on the basis of x-ray diffraction data, is arranged n a coiled-coil conformation characteristic of proteins of the a type. The known structural properties such as morphology, dimensions, subunit composition, and ultrastructure of this fibrous protein are very similar to those of the mammalian epidermal keratin filament, to which it may therefore be related. It is now apparent that all eukaryotic cell types contain at least three different types of intracellular structural proteins: microtubules (about 25 nm in diameter), actin-containing microfilaments (about 5-7 nm in diameter), and a less-characterized class of filaments of intermediate dimensions (7)(8)(9)(10)(11)(12) (6,14,15,21,22), and cell locomotion in cultured cells (2,17,18). In more specialized cells such as keratinocytes, these filaments comprise up to 70% of the total cellular mass (19,23) and, through interconnections between desmosomes, appear to lend a rigid or flexible texture to the tissue (19,24).The grouping of 10-nm filaments, neurofilaments, tonofilaments and other intermediate filaments into a class of similar fibrous proteins has been based almost exclusively on similarities in morphology and amino acid compositions of major subunits (4,17). Therefore, it is of considerable importance to use more quantitative chemical and structural techniques to determine the extent of homology within this class from different cell types. In the cells studied to date, the reported numbers of filament subunits vary from one to a large number, and their molecular weights are within the range 45,000-212,000 (4,5). However, it is unclear whether these differences are real, as suggested by peptide mapping (25), or artifacts due to peptide degradation (13).While comparatively little is known of the structure of this class of filaments from most cell types, knowledge of the structure of keratin filaments from both hair (and wool) and epidermis is now well advanced (26,27). Thus consideration and comparison of the properties-of keratin filaments with those of the similar-sized filaments from other cell types may be useful. Keratin filaments are a-helix-rich fibrous proteins that exhibit an a type x-ray diffraction pattern characteristic of proteins of the k ("hard" keratin)-m (myosin)-e (epidermin = epidermal keratin)-f (fibrin) class (19,28). This x-ray diffraction pattern has been interpreted in terms of models in which a-helical regions of the subunits are arranged in a twoor three-strandedl supercoiled or coiled-coil conformation (29,30). Direct evidence for this concept stems from the more recent characterization of a-helix-rich regions containing two (31, 32) or three coiled-coil chains (27,33,34) (X240,000). (C) Transverse cross-section through a fiber used for x-ray diffraction. (X240,000.) In A-C, the bar is 0. 1.um.(D) ...

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A Conformation-dependent Cotton Effect in α-Helical Polypeptides and Proteins^1,2

Cited by 216 publications

References 0 publications

Physical Chemical Studies on Proteins and Polypeptides

Physical Chemical Studies on Proteins and Polypeptides

Growth of L929 cells on polymeric films prepared by Langmuir–Blodgett and casting methods

Ten-nanometer filaments of hamster BHK-21 cells and epidermal keratin filaments have similar structures.

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A Conformation-dependent Cotton Effect in α-Helical Polypeptides and Proteins1,2

Cited by 216 publications

References 0 publications

Physical Chemical Studies on Proteins and Polypeptides

Physical Chemical Studies on Proteins and Polypeptides

Growth of L929 cells on polymeric films prepared by Langmuir–Blodgett and casting methods

Ten-nanometer filaments of hamster BHK-21 cells and epidermal keratin filaments have similar structures.

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Product

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A Conformation-dependent Cotton Effect in α-Helical Polypeptides and Proteins^1,2