Candidacidal activity prompted by N-terminus histatin-like domain of human salivary mucin (MUC7)

Tarikere L. Gururaja, Joseph H. Levine, Duy T. Tran, Gowda A. Naganagowda, Kalaiyarasi Ramalingam, Narayanan Ramasubbu, Michael J. Levine

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Histidine-rich peptides (histatins, Hsn) in saliva are thought to provide a non-immune defense against Candida albicans. Sequence homology search of the human salivary mucin, MUC7, against histatins revealed a domain at the N-terminus (R3-Q17) having 53% identity to Hsn-5. To determine its candidacidal activity, this 15 residue basic histidine-rich domain of MUC7 (I) was prepared by solid-phase Fmoc chemistry. Various N- and C-terminal protected derivatives of I were also synthesized to correlate the effect of peptide overall charge in exhibiting cidal potency. Candidacidal activity measurement of I and its variants showed considerable ED50 values (effective dosage required to kill 50% of candida cells), albeit greater than Hsn-5 (ED50 ~4-6 μM). Of the various analogs tested, N-terminal free acid (I, ED50 ~40 μM) and amide (V, ED50~16 μM) exhibited appreciable candidacidal activities suggesting the possible role of peptide net charge in cidal action. Blocking of N-terminus with a bulky octanoyl group showed only marginal effect on the cidal activity of I or V, indicating that hydrophobicity of these synthetic constructs may not be important for exerting such activities. Membrane-induced conformational transition from random coil to helical structures of all the test peptides implied their tendency to adapt order structures at the lipid-membrane interface similar to that of Hsn-5. However, comparison of propensity for helical structure formation vs. ED50 indicated that cidal potency of MUC7 Hsn-like peptides depends largely on electrostatic interactions irrespective of secondary structural elements. Delineation of solution structure of the most active peptide (V) by 2D-NMR revealed essentially a non-structured conformation in aqueous medium, which further supported the fact that the peptide helical structure may not be a prerequisite for posing candidacidal activity. The formation of smaller truncated peptides and/or Hsn-like fragments on proteolytic degradation of intact MUC7 in the presence of oral flora provided indirect evidence that mucin could serve as a backup candidacidal agent to salivary Hsn. Copyright (C) 1999 Elsevier Science B.V.

Original languageEnglish (US)
Pages (from-to)107-119
Number of pages13
JournalBiochimica et Biophysica Acta - Protein Structure and Molecular Enzymology
Volume1431
Issue number1
DOIs
StatePublished - Apr 12 1999

Fingerprint

Histatins
Mucins
Peptides
Candida
Histidine
Hydrophobicity
Membrane Lipids
Sequence Homology
Coulomb interactions
Static Electricity
Candida albicans
Hydrophobic and Hydrophilic Interactions
Saliva
Amides
Conformations
Nuclear magnetic resonance
Derivatives
Membranes

All Science Journal Classification (ASJC) codes

  • Structural Biology
  • Biophysics
  • Biochemistry
  • Molecular Biology

Keywords

  • 2D-NMR
  • Candida albicans
  • Candidacidal activity
  • Circular dichroism
  • Histatin-like domain
  • Human salivary mucin
  • Peptide synthesis
  • Solution conformation

Cite this

Gururaja, Tarikere L. ; Levine, Joseph H. ; Tran, Duy T. ; Naganagowda, Gowda A. ; Ramalingam, Kalaiyarasi ; Ramasubbu, Narayanan ; Levine, Michael J. / Candidacidal activity prompted by N-terminus histatin-like domain of human salivary mucin (MUC7). In: Biochimica et Biophysica Acta - Protein Structure and Molecular Enzymology. 1999 ; Vol. 1431, No. 1. pp. 107-119.
@article{8e6db50c7f3e4c0d975db3c0ebf82822,
title = "Candidacidal activity prompted by N-terminus histatin-like domain of human salivary mucin (MUC7)",
abstract = "Histidine-rich peptides (histatins, Hsn) in saliva are thought to provide a non-immune defense against Candida albicans. Sequence homology search of the human salivary mucin, MUC7, against histatins revealed a domain at the N-terminus (R3-Q17) having 53{\%} identity to Hsn-5. To determine its candidacidal activity, this 15 residue basic histidine-rich domain of MUC7 (I) was prepared by solid-phase Fmoc chemistry. Various N- and C-terminal protected derivatives of I were also synthesized to correlate the effect of peptide overall charge in exhibiting cidal potency. Candidacidal activity measurement of I and its variants showed considerable ED50 values (effective dosage required to kill 50{\%} of candida cells), albeit greater than Hsn-5 (ED50 ~4-6 μM). Of the various analogs tested, N-terminal free acid (I, ED50 ~40 μM) and amide (V, ED50~16 μM) exhibited appreciable candidacidal activities suggesting the possible role of peptide net charge in cidal action. Blocking of N-terminus with a bulky octanoyl group showed only marginal effect on the cidal activity of I or V, indicating that hydrophobicity of these synthetic constructs may not be important for exerting such activities. Membrane-induced conformational transition from random coil to helical structures of all the test peptides implied their tendency to adapt order structures at the lipid-membrane interface similar to that of Hsn-5. However, comparison of propensity for helical structure formation vs. ED50 indicated that cidal potency of MUC7 Hsn-like peptides depends largely on electrostatic interactions irrespective of secondary structural elements. Delineation of solution structure of the most active peptide (V) by 2D-NMR revealed essentially a non-structured conformation in aqueous medium, which further supported the fact that the peptide helical structure may not be a prerequisite for posing candidacidal activity. The formation of smaller truncated peptides and/or Hsn-like fragments on proteolytic degradation of intact MUC7 in the presence of oral flora provided indirect evidence that mucin could serve as a backup candidacidal agent to salivary Hsn. Copyright (C) 1999 Elsevier Science B.V.",
keywords = "2D-NMR, Candida albicans, Candidacidal activity, Circular dichroism, Histatin-like domain, Human salivary mucin, Peptide synthesis, Solution conformation",
author = "Gururaja, {Tarikere L.} and Levine, {Joseph H.} and Tran, {Duy T.} and Naganagowda, {Gowda A.} and Kalaiyarasi Ramalingam and Narayanan Ramasubbu and Levine, {Michael J.}",
year = "1999",
month = "4",
day = "12",
doi = "10.1016/S0167-4838(99)00034-5",
language = "English (US)",
volume = "1431",
pages = "107--119",
journal = "Biochimica et Biophysica Acta - Proteins and Proteomics",
issn = "1570-9639",
publisher = "Elsevier",
number = "1",

}

Candidacidal activity prompted by N-terminus histatin-like domain of human salivary mucin (MUC7). / Gururaja, Tarikere L.; Levine, Joseph H.; Tran, Duy T.; Naganagowda, Gowda A.; Ramalingam, Kalaiyarasi; Ramasubbu, Narayanan; Levine, Michael J.

In: Biochimica et Biophysica Acta - Protein Structure and Molecular Enzymology, Vol. 1431, No. 1, 12.04.1999, p. 107-119.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Candidacidal activity prompted by N-terminus histatin-like domain of human salivary mucin (MUC7)

AU - Gururaja, Tarikere L.

AU - Levine, Joseph H.

AU - Tran, Duy T.

AU - Naganagowda, Gowda A.

AU - Ramalingam, Kalaiyarasi

AU - Ramasubbu, Narayanan

AU - Levine, Michael J.

PY - 1999/4/12

Y1 - 1999/4/12

N2 - Histidine-rich peptides (histatins, Hsn) in saliva are thought to provide a non-immune defense against Candida albicans. Sequence homology search of the human salivary mucin, MUC7, against histatins revealed a domain at the N-terminus (R3-Q17) having 53% identity to Hsn-5. To determine its candidacidal activity, this 15 residue basic histidine-rich domain of MUC7 (I) was prepared by solid-phase Fmoc chemistry. Various N- and C-terminal protected derivatives of I were also synthesized to correlate the effect of peptide overall charge in exhibiting cidal potency. Candidacidal activity measurement of I and its variants showed considerable ED50 values (effective dosage required to kill 50% of candida cells), albeit greater than Hsn-5 (ED50 ~4-6 μM). Of the various analogs tested, N-terminal free acid (I, ED50 ~40 μM) and amide (V, ED50~16 μM) exhibited appreciable candidacidal activities suggesting the possible role of peptide net charge in cidal action. Blocking of N-terminus with a bulky octanoyl group showed only marginal effect on the cidal activity of I or V, indicating that hydrophobicity of these synthetic constructs may not be important for exerting such activities. Membrane-induced conformational transition from random coil to helical structures of all the test peptides implied their tendency to adapt order structures at the lipid-membrane interface similar to that of Hsn-5. However, comparison of propensity for helical structure formation vs. ED50 indicated that cidal potency of MUC7 Hsn-like peptides depends largely on electrostatic interactions irrespective of secondary structural elements. Delineation of solution structure of the most active peptide (V) by 2D-NMR revealed essentially a non-structured conformation in aqueous medium, which further supported the fact that the peptide helical structure may not be a prerequisite for posing candidacidal activity. The formation of smaller truncated peptides and/or Hsn-like fragments on proteolytic degradation of intact MUC7 in the presence of oral flora provided indirect evidence that mucin could serve as a backup candidacidal agent to salivary Hsn. Copyright (C) 1999 Elsevier Science B.V.

AB - Histidine-rich peptides (histatins, Hsn) in saliva are thought to provide a non-immune defense against Candida albicans. Sequence homology search of the human salivary mucin, MUC7, against histatins revealed a domain at the N-terminus (R3-Q17) having 53% identity to Hsn-5. To determine its candidacidal activity, this 15 residue basic histidine-rich domain of MUC7 (I) was prepared by solid-phase Fmoc chemistry. Various N- and C-terminal protected derivatives of I were also synthesized to correlate the effect of peptide overall charge in exhibiting cidal potency. Candidacidal activity measurement of I and its variants showed considerable ED50 values (effective dosage required to kill 50% of candida cells), albeit greater than Hsn-5 (ED50 ~4-6 μM). Of the various analogs tested, N-terminal free acid (I, ED50 ~40 μM) and amide (V, ED50~16 μM) exhibited appreciable candidacidal activities suggesting the possible role of peptide net charge in cidal action. Blocking of N-terminus with a bulky octanoyl group showed only marginal effect on the cidal activity of I or V, indicating that hydrophobicity of these synthetic constructs may not be important for exerting such activities. Membrane-induced conformational transition from random coil to helical structures of all the test peptides implied their tendency to adapt order structures at the lipid-membrane interface similar to that of Hsn-5. However, comparison of propensity for helical structure formation vs. ED50 indicated that cidal potency of MUC7 Hsn-like peptides depends largely on electrostatic interactions irrespective of secondary structural elements. Delineation of solution structure of the most active peptide (V) by 2D-NMR revealed essentially a non-structured conformation in aqueous medium, which further supported the fact that the peptide helical structure may not be a prerequisite for posing candidacidal activity. The formation of smaller truncated peptides and/or Hsn-like fragments on proteolytic degradation of intact MUC7 in the presence of oral flora provided indirect evidence that mucin could serve as a backup candidacidal agent to salivary Hsn. Copyright (C) 1999 Elsevier Science B.V.

KW - 2D-NMR

KW - Candida albicans

KW - Candidacidal activity

KW - Circular dichroism

KW - Histatin-like domain

KW - Human salivary mucin

KW - Peptide synthesis

KW - Solution conformation

UR - http://www.scopus.com/inward/record.url?scp=0032934508&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032934508&partnerID=8YFLogxK

U2 - 10.1016/S0167-4838(99)00034-5

DO - 10.1016/S0167-4838(99)00034-5

M3 - Article

VL - 1431

SP - 107

EP - 119

JO - Biochimica et Biophysica Acta - Proteins and Proteomics

JF - Biochimica et Biophysica Acta - Proteins and Proteomics

SN - 1570-9639

IS - 1

ER -