Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-2-27
pubmed:abstractText
At ejaculation, PDC-109, the major heparin-binding protein of bull seminal plasma, binds to the phosphorylcholine group of sperm lipids and modulates capacitation promoted by glycosaminoglycans during sperm residence in the female genital tract. Combination of size-exclusion chromatography, analytical ultracentrifugation, circular dichroism, Fourier-transform infrared spectroscopy, and differential scanning calorimetry has allowed us to biophysically characterize PDC-109 and its interaction with phosphorylcholine. PDC-109 can be regarded as a polydisperse molecule whose aggregation state can be modulated by the solute composition of its solution environment. Dissociation of PDC-109 oligomers occurs upon increasing the concentration of either NaCl, EDTA, CaCl2, or phosphorylcholine, suggesting that both ionic and hydrophobic interactions are responsible for the aggregation tendency of PDC-109 monomers. Dissociation processes are accompanied by exposure of peptide bonds to the solvent, changes in the environment of tyrosine and tryptophan residues, and a slight increase in the turn content at the expense of non-regular structure. Analysis of the heat-induced denaturation of PDC-109 oligomers revealed two melting transitions at about 36 degrees C (irreversible) and 55 degrees C (partially reversible) characterized by calorimetric enthalpy changes of 42 kJ/mol and 217 kJ/mol, respectively. These transitions could be assigned to the dissociation of oligomers and to the cooperative unfolding of PDC-109 monomers, respectively. The modulation of the aggregation state of PDC-109 by its molecular environment and by phosphorylcholine binding suggests possible mechanisms for capacitation mediated by the seminal plasma protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
250
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
735-44
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed-meshheading:9461296-Animals, pubmed-meshheading:9461296-Calorimetry, Differential Scanning, pubmed-meshheading:9461296-Cattle, pubmed-meshheading:9461296-Chromatography, Gel, pubmed-meshheading:9461296-Circular Dichroism, pubmed-meshheading:9461296-Male, pubmed-meshheading:9461296-Molecular Weight, pubmed-meshheading:9461296-Phosphorylcholine, pubmed-meshheading:9461296-Prostatic Secretory Proteins, pubmed-meshheading:9461296-Protein Binding, pubmed-meshheading:9461296-Protein Conformation, pubmed-meshheading:9461296-Protein Denaturation, pubmed-meshheading:9461296-Protein Folding, pubmed-meshheading:9461296-Protein Structure, Secondary, pubmed-meshheading:9461296-Protein Structure, Tertiary, pubmed-meshheading:9461296-Proteins, pubmed-meshheading:9461296-Semen, pubmed-meshheading:9461296-Seminal Plasma Proteins, pubmed-meshheading:9461296-Spectroscopy, Fourier Transform Infrared, pubmed-meshheading:9461296-Sperm Capacitation, pubmed-meshheading:9461296-Temperature, pubmed-meshheading:9461296-Thermodynamics, pubmed-meshheading:9461296-Ultracentrifugation
pubmed:year
1997
pubmed:articleTitle
Conformational features and thermal stability of bovine seminal plasma protein PDC-109 oligomers and phosphorylcholine-bound complexes.
pubmed:affiliation
Instituto de Quìmica-Fìsica Rocasolano, CSIC, Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't