Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus

A peptide with the sequence Cys-Thr-Leu-Thr-Thr-Lys-Leu-Tyr-Cys (CTLTTKLYC) has previously been identified to inhibit the propagation of Newcastle disease virus (NDV) in embryonated chicken eggs and tissue culture. It has two different dissociation constants (&"I), in which the first con...

Full description

Saved in:

Bibliographic Details
Main Author:	Chia, Suet Lin
Format:	Thesis
Language:	English
Published:	2005
Subjects:	Newcastle disease virus
Online Access:	http://psasir.upm.edu.my/id/eprint/5942/1/FBSB_2005_22%20IR.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-upm-ir.5942
record_format	uketd_dc
spelling	my-upm-ir.59422022-02-10T02:06:07Z Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus 2005-06 Chia, Suet Lin A peptide with the sequence Cys-Thr-Leu-Thr-Thr-Lys-Leu-Tyr-Cys (CTLTTKLYC) has previously been identified to inhibit the propagation of Newcastle disease virus (NDV) in embryonated chicken eggs and tissue culture. It has two different dissociation constants (&"I), in which the first constant can be used as a determinant to classifjr NDV strains into two groups: the velogenic strains in the first group, whereas the mesogenic and lentogenic strains are in the second group. The peptide, C 1T 2L3 P T5K 6 L7 Y8 C9 ,d isplayed on the pIII protein of a filamentous M13 phage was mutated by oligonucleotide-directed mutagenesis in order to identify the amino acid residues involved in the interactions with NDV. Mutations of Cys at first position (c')a nd Lys at the sixth position of the peptide ( K ~t)o Ala (A), which produced mutants C'A and K~Ad,i d not affect the binding between the peptide and the virus significantly, but substitution of Tyr at eighth position (Y8) alone with Ala (A) dramatically reduced the interaction. This suggests that y8 couid play an important role in the peptide-virus interaction. Double mutations were carried out on K~ and y8 to produce mutants K~A-Y~AK,~ R-Y~AK,~ A-Y'F, and K ~ - Y ~ Fto, determine whether the mutated amino acids could improve the binding capability. However, the mutations did not improve the binding capability significantly. Fmoc-solid phase peptide synthesis was employed to synthesize the peptide, CTLTTKLYC. Crude peptide was purified with HPLC and analysed with a mass spectrometer. The secondary structure of the peptide was analysed with circular dichroism (CD) and the three dimensional conformation of the peptide was determined by nuclear magnetic resonance (NMR) and molecular modelling. A mixture conformation of p-turn and P-sheet (intermolecular interaction) was observed for the linear peptide by using CD. However, the three-dimensional structure of the linear peptide could not be arrived due to the mixture of conformation which made the sequence assignment of NMR extremely difficult. On the other hand, the disulfide-constrained cyclic peptide, which has a more rigid structure, exhibited only a P-turn structure. Two models were obtained: one of it consists of a p-turn and a distorted p-turn, while the other structure is an extended structure. Newcastle disease virus 2005-06 Thesis http://psasir.upm.edu.my/id/eprint/5942/ http://psasir.upm.edu.my/id/eprint/5942/1/FBSB_2005_22%20IR.pdf text en public masters Universiti Putra Malaysia Newcastle disease virus Faculty of Biotechnology and Biomokular Sciences Yusoff, Khatijah
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
advisor	Yusoff, Khatijah
topic	Newcastle disease virus
spellingShingle	Newcastle disease virus Chia, Suet Lin Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus
description	A peptide with the sequence Cys-Thr-Leu-Thr-Thr-Lys-Leu-Tyr-Cys (CTLTTKLYC) has previously been identified to inhibit the propagation of Newcastle disease virus (NDV) in embryonated chicken eggs and tissue culture. It has two different dissociation constants (&"I), in which the first constant can be used as a determinant to classifjr NDV strains into two groups: the velogenic strains in the first group, whereas the mesogenic and lentogenic strains are in the second group. The peptide, C 1T 2L3 P T5K 6 L7 Y8 C9 ,d isplayed on the pIII protein of a filamentous M13 phage was mutated by oligonucleotide-directed mutagenesis in order to identify the amino acid residues involved in the interactions with NDV. Mutations of Cys at first position (c')a nd Lys at the sixth position of the peptide ( K ~t)o Ala (A), which produced mutants C'A and K~Ad,i d not affect the binding between the peptide and the virus significantly, but substitution of Tyr at eighth position (Y8) alone with Ala (A) dramatically reduced the interaction. This suggests that y8 couid play an important role in the peptide-virus interaction. Double mutations were carried out on K~ and y8 to produce mutants K~A-Y~AK,~ R-Y~AK,~ A-Y'F, and K ~ - Y ~ Fto, determine whether the mutated amino acids could improve the binding capability. However, the mutations did not improve the binding capability significantly. Fmoc-solid phase peptide synthesis was employed to synthesize the peptide, CTLTTKLYC. Crude peptide was purified with HPLC and analysed with a mass spectrometer. The secondary structure of the peptide was analysed with circular dichroism (CD) and the three dimensional conformation of the peptide was determined by nuclear magnetic resonance (NMR) and molecular modelling. A mixture conformation of p-turn and P-sheet (intermolecular interaction) was observed for the linear peptide by using CD. However, the three-dimensional structure of the linear peptide could not be arrived due to the mixture of conformation which made the sequence assignment of NMR extremely difficult. On the other hand, the disulfide-constrained cyclic peptide, which has a more rigid structure, exhibited only a P-turn structure. Two models were obtained: one of it consists of a p-turn and a distorted p-turn, while the other structure is an extended structure.
format	Thesis
qualification_level	Master's degree
author	Chia, Suet Lin
author_facet	Chia, Suet Lin
author_sort	Chia, Suet Lin
title	Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus
title_short	Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus
title_full	Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus
title_fullStr	Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus
title_full_unstemmed	Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus
title_sort	structural analysis of a peptide (ctlttklyc) that interacts with newcastle disease virus
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Biotechnology and Biomokular Sciences
publishDate	2005
url	http://psasir.upm.edu.my/id/eprint/5942/1/FBSB_2005_22%20IR.pdf
_version_	1747810512861659136

Structural Analysis of a Peptide (CTLTTKLYC) that Interacts with Newcastle Disease Virus

Similar Items