Tapping mode atomic force microscopy of scleroglucan networks

A. K. Vuppu, Antonio Garcia, C. Vernia

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Tapping mode Atomic Force Microscopy (TmAFM) has been used to study the fungal polysaccharide scleroglucan deposited from aqueous solution and dimethyl sulfoxide (DMSO) onto a mica surface. The solutions from which the microscope samples were produced were prepared by first dissolving the solid scleroglucan in 0.1M NaOH, then neutralizing the solution with HCl, followed by dilution to the required concentration in either water or DMSO. It was found that from the aqueous solution described above, scleroglucan forms networks. Based on a comparison of the denatured-renatured and aqueous solution samples, network formation is due to the imperfect registration between the chains forming the triple helices. The relatively large stiffness of the scleroglucan triple helix is also assumed to contribute to the formation of the extended networks. The triple helix diameter was measured to be 0.92 ± 0.27 nm, which is in the same range as that obtained by other researchers using similar techniques. Denatured scleroglucan, deposited from DMSO onto mica, forms a web-like layer on top of which there are sphere-like structures. These morphologies are believed to be due to triple helix denaturation yielding highly flexible single chains in DMSO, which results in coiling and web-like dense packing of scleroglucan upon deposition onto mica. Most interestingly after addition of water to the samples deposited from DMSO, some of the chains can be renatured into short, stiff rod-like structures which are similar to the structures observed by other researchers. The imaging data for aqueous solution deposition can be analyzed by plotting maximum end-to-end distance versus the perimeter of the networks deposited onto mica. This yields a Flory-like exponent of 0.67, which is almost similar in value to that obtained by other researchers for linear structures of scleroglucan but less than that expected for a polymer chain following a self-avoiding walk (v = 0.75) model on a two-dimensional surface. The fractal dimension that can be used to characterize the networks was determined graphically to be 1.22 ± 0.06.

Original languageEnglish (US)
Pages (from-to)89-100
Number of pages12
JournalBiopolymers
Volume42
Issue number1
DOIs
StatePublished - Jul 1997

Fingerprint

Atomic Force Microscopy
Dimethyl sulfoxide
Atomic force microscopy
Mica
Dimethyl Sulfoxide
Research Personnel
Fungal Polysaccharides
Denaturation
Fractals
Fractal dimension
Polysaccharides
Water
Dilution
scleroglucan
Microscopes
Stiffness
Polymers
Imaging techniques
mica

Keywords

  • Denaturation- renaturation
  • Fractal dimension
  • Scleroglucan networks
  • Tapping mode atomic force microscopy

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biophysics

Cite this

Tapping mode atomic force microscopy of scleroglucan networks. / Vuppu, A. K.; Garcia, Antonio; Vernia, C.

In: Biopolymers, Vol. 42, No. 1, 07.1997, p. 89-100.

Research output: Contribution to journalArticle

Vuppu, A. K. ; Garcia, Antonio ; Vernia, C. / Tapping mode atomic force microscopy of scleroglucan networks. In: Biopolymers. 1997 ; Vol. 42, No. 1. pp. 89-100.
@article{245bbe06933a4a5f8162c9ca7a6deff4,
title = "Tapping mode atomic force microscopy of scleroglucan networks",
abstract = "Tapping mode Atomic Force Microscopy (TmAFM) has been used to study the fungal polysaccharide scleroglucan deposited from aqueous solution and dimethyl sulfoxide (DMSO) onto a mica surface. The solutions from which the microscope samples were produced were prepared by first dissolving the solid scleroglucan in 0.1M NaOH, then neutralizing the solution with HCl, followed by dilution to the required concentration in either water or DMSO. It was found that from the aqueous solution described above, scleroglucan forms networks. Based on a comparison of the denatured-renatured and aqueous solution samples, network formation is due to the imperfect registration between the chains forming the triple helices. The relatively large stiffness of the scleroglucan triple helix is also assumed to contribute to the formation of the extended networks. The triple helix diameter was measured to be 0.92 ± 0.27 nm, which is in the same range as that obtained by other researchers using similar techniques. Denatured scleroglucan, deposited from DMSO onto mica, forms a web-like layer on top of which there are sphere-like structures. These morphologies are believed to be due to triple helix denaturation yielding highly flexible single chains in DMSO, which results in coiling and web-like dense packing of scleroglucan upon deposition onto mica. Most interestingly after addition of water to the samples deposited from DMSO, some of the chains can be renatured into short, stiff rod-like structures which are similar to the structures observed by other researchers. The imaging data for aqueous solution deposition can be analyzed by plotting maximum end-to-end distance versus the perimeter of the networks deposited onto mica. This yields a Flory-like exponent of 0.67, which is almost similar in value to that obtained by other researchers for linear structures of scleroglucan but less than that expected for a polymer chain following a self-avoiding walk (v = 0.75) model on a two-dimensional surface. The fractal dimension that can be used to characterize the networks was determined graphically to be 1.22 ± 0.06.",
keywords = "Denaturation- renaturation, Fractal dimension, Scleroglucan networks, Tapping mode atomic force microscopy",
author = "Vuppu, {A. K.} and Antonio Garcia and C. Vernia",
year = "1997",
month = "7",
doi = "10.1002/(SICI)1097-0282(199707)42:1<89::AID-BIP8>3.0.CO;2-Y",
language = "English (US)",
volume = "42",
pages = "89--100",
journal = "Biopolymers - Peptide Science Section",
issn = "0006-3525",
publisher = "John Wiley and Sons Inc.",
number = "1",

}

TY - JOUR

T1 - Tapping mode atomic force microscopy of scleroglucan networks

AU - Vuppu, A. K.

AU - Garcia, Antonio

AU - Vernia, C.

PY - 1997/7

Y1 - 1997/7

N2 - Tapping mode Atomic Force Microscopy (TmAFM) has been used to study the fungal polysaccharide scleroglucan deposited from aqueous solution and dimethyl sulfoxide (DMSO) onto a mica surface. The solutions from which the microscope samples were produced were prepared by first dissolving the solid scleroglucan in 0.1M NaOH, then neutralizing the solution with HCl, followed by dilution to the required concentration in either water or DMSO. It was found that from the aqueous solution described above, scleroglucan forms networks. Based on a comparison of the denatured-renatured and aqueous solution samples, network formation is due to the imperfect registration between the chains forming the triple helices. The relatively large stiffness of the scleroglucan triple helix is also assumed to contribute to the formation of the extended networks. The triple helix diameter was measured to be 0.92 ± 0.27 nm, which is in the same range as that obtained by other researchers using similar techniques. Denatured scleroglucan, deposited from DMSO onto mica, forms a web-like layer on top of which there are sphere-like structures. These morphologies are believed to be due to triple helix denaturation yielding highly flexible single chains in DMSO, which results in coiling and web-like dense packing of scleroglucan upon deposition onto mica. Most interestingly after addition of water to the samples deposited from DMSO, some of the chains can be renatured into short, stiff rod-like structures which are similar to the structures observed by other researchers. The imaging data for aqueous solution deposition can be analyzed by plotting maximum end-to-end distance versus the perimeter of the networks deposited onto mica. This yields a Flory-like exponent of 0.67, which is almost similar in value to that obtained by other researchers for linear structures of scleroglucan but less than that expected for a polymer chain following a self-avoiding walk (v = 0.75) model on a two-dimensional surface. The fractal dimension that can be used to characterize the networks was determined graphically to be 1.22 ± 0.06.

AB - Tapping mode Atomic Force Microscopy (TmAFM) has been used to study the fungal polysaccharide scleroglucan deposited from aqueous solution and dimethyl sulfoxide (DMSO) onto a mica surface. The solutions from which the microscope samples were produced were prepared by first dissolving the solid scleroglucan in 0.1M NaOH, then neutralizing the solution with HCl, followed by dilution to the required concentration in either water or DMSO. It was found that from the aqueous solution described above, scleroglucan forms networks. Based on a comparison of the denatured-renatured and aqueous solution samples, network formation is due to the imperfect registration between the chains forming the triple helices. The relatively large stiffness of the scleroglucan triple helix is also assumed to contribute to the formation of the extended networks. The triple helix diameter was measured to be 0.92 ± 0.27 nm, which is in the same range as that obtained by other researchers using similar techniques. Denatured scleroglucan, deposited from DMSO onto mica, forms a web-like layer on top of which there are sphere-like structures. These morphologies are believed to be due to triple helix denaturation yielding highly flexible single chains in DMSO, which results in coiling and web-like dense packing of scleroglucan upon deposition onto mica. Most interestingly after addition of water to the samples deposited from DMSO, some of the chains can be renatured into short, stiff rod-like structures which are similar to the structures observed by other researchers. The imaging data for aqueous solution deposition can be analyzed by plotting maximum end-to-end distance versus the perimeter of the networks deposited onto mica. This yields a Flory-like exponent of 0.67, which is almost similar in value to that obtained by other researchers for linear structures of scleroglucan but less than that expected for a polymer chain following a self-avoiding walk (v = 0.75) model on a two-dimensional surface. The fractal dimension that can be used to characterize the networks was determined graphically to be 1.22 ± 0.06.

KW - Denaturation- renaturation

KW - Fractal dimension

KW - Scleroglucan networks

KW - Tapping mode atomic force microscopy

UR - http://www.scopus.com/inward/record.url?scp=0031195001&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031195001&partnerID=8YFLogxK

U2 - 10.1002/(SICI)1097-0282(199707)42:1<89::AID-BIP8>3.0.CO;2-Y

DO - 10.1002/(SICI)1097-0282(199707)42:1<89::AID-BIP8>3.0.CO;2-Y

M3 - Article

C2 - 9209159

AN - SCOPUS:0031195001

VL - 42

SP - 89

EP - 100

JO - Biopolymers - Peptide Science Section

JF - Biopolymers - Peptide Science Section

SN - 0006-3525

IS - 1

ER -