Investigation of amino acid composition in the crystalline region of silk fibroin

Nadiger, G. S.; Bhat, N. V.; Padhye, M. R.

doi:10.1002/app.1985.070300118

Cited by 13 publications

(13 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the amino acid composition chart compiled from past studies (Table I), it is evident that the most important metal binding ligands, Histidine and Tryptophan are at higher ratios in Eri silk than found in Mulberry silk 41–44. Other amino acids in these proteins that are reported to play a role in metal binding include phenylalanine, tyrosine,19 arginine, and lysine18, 19 and aspartic and glutamic acids 4, 17, 18.…”

Section: Resultsmentioning

confidence: 99%

An investigation into transition metal ion binding properties of silk fibers and particles using radioisotopes

Rajkhowa

Naik

Wang

et al. 2010

J of Applied Polymer Sci

View full text Add to dashboard Cite

Silk is a structural protein fiber that is stable over a wide pH range making it attractive for use in medical and environmental applications. Variation in amino acid composition has the potential for selective binding for ions under varying conditions. Here we report on the metal ion separation potential of Mulberry and Eri silk fibers and powders over a range of pH. Highly sensitive radiotracer probes, . In all cases the silk powders absorbed metal ions faster than their respective silk fibers. Intensive degumming of the fibers and powders significantly reduced the time to absorb respective metal ions and the time to reach equilibrium was reduced from hours to 5-15 min at pH 8. Once bound, 45-100% of the metal ions were released from the sorbents after exposure to pH 3 buffer for 30 min. The transition metal ion loading capacity for the silk sorbents was considerably higher than that found for commercial ion exchange resins (AG MP-50 and AG 50W-X2) under similar conditions. Interestingly, total Cu 2þ bound was found to be higher than theoretically predicted values based on known specific Cu 2þ binding sites (AHGGYSGY), suggesting that additional (new) sites for transition metal ion binding sites are present in silk fibers.

show abstract

Section: Resultsmentioning

confidence: 99%

An investigation into transition metal ion binding properties of silk fibers and particles using radioisotopes

Rajkhowa

Naik

Wang

et al. 2010

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Detailed studies of amino acid composition were made by Nadiger et al 15 first on the silk fibroin in the four varieties of Indian silk fibers and second of the crystalline regions of silk fibers obtained by partial acid hydrolysis. Their main conclusions, which are consistent with the results obtained by Shaw and Smith, 16 may be summarized under the following two headings:…”

Section: X-ray Diffraction Datamentioning

confidence: 99%

Tensile stress-strain and recovery behavior of Indian silk fibers and their structural dependence

Rajkhowa

Gupta

Kothari

2000

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

“…The results of the above studies indicated that the fibroins of Bombyx mori type are characterized by the presence of glycine, alanine, and serine in the crystalline regions. In their work on selective acid hydrolysis of Indian silk, Nadiger et al 15 showed that in the crystalline regions, the composition of the above three amino acids was about 91% for mulberry, about 81-82% for tasar and muga, and about 77% for eri.…”

Section: Introductionmentioning

confidence: 98%

Studies on Indian silk. I. Macrocharacterization and analysis of amino acid composition

Sen

K²

2004

J of Applied Polymer Sci

126

110

View full text Add to dashboard Cite

This first in a series of articles characterized the different varieties of Indian silk for their macrostructural parameters, such as filament length, degumming loss, denier, cross section, moisture regain, and intrinsic viscosity, for example. The results of amino acid analysis using a reverse-phase technique were also reported. Five Indian silk varieties-two mulberry (bivoltine and crossbreed) and three nonmulberry (tasar, muga, and eri)-were investigated. The differences existing between the different varieties and the extent of lengthwise variations within a cocoon in the dimensional and macrostructural parameters were discussed. It was observed that denier of the filament decreases considerably from the outer to the inner layers, whereas density showed an increasing trend in all the varieties. Both the mulberry silks demonstrated lower moisture regain. Electron micrographs of all the nonmulberry varieties showed microvoids in their cross section. Fraction studies showed the development of mushroom structure on the tips. In both types of mulberry silk, glycine, alanine, and serine constitute about 82% of the amino acids present. On the other hand, in nonmulberry silks, these constitute about 73% with a high proportion of alanine. The nonmulberry varieties showed a substantial proportion of amino acids with bulky side groups. Similarly, the higher hydrophilic to hydrophobic amino acid ratio (9.06 -9.85) for nonmulberry silks, compared against that of the mulberry varieties (5.29 -6.22), was shown to be responsible for the higher moisture content of nonmulberry silks. Cystine and methionine were present in all the varieties. The higher intrinsic viscosity of nonmulberry varieties suggested their higher molecular weight. Through amino acid analysis, it was shown that there is no difference in chemical architecture between the outer and the inner layers of cocoons.

show abstract

Investigation of amino acid composition in the crystalline region of silk fibroin

Cited by 13 publications

References 4 publications

An investigation into transition metal ion binding properties of silk fibers and particles using radioisotopes

An investigation into transition metal ion binding properties of silk fibers and particles using radioisotopes

Tensile stress-strain and recovery behavior of Indian silk fibers and their structural dependence

Studies on Indian silk. I. Macrocharacterization and analysis of amino acid composition

Contact Info

Product

Resources

About