Biomedical subjects

M T Gallego

Publications and source records attributed to M T Gallego.

5 recordsLinked to original sources

PubMed2002

Pru p 3 (LTP) content in peach extracts.

BACKGROUND: Lipid transfer proteins are molecules widely distributed in fruits. Sensitization to LTP is frequent in fruit sensitive patients. The aims of this study were to purify LTP and to assess the content of LTP in ripe peach peel and pulp extracts by ELISA inhibition using polyclonal antibodies. METHODS: LTP was purified from ripe yellow peach peel by two different column chromatography methods. A polyclonal antibody was produced by injecting purified LTP into two New Zealand white rabbits. ELISA inhibition and rabbit monospecific polyclonal antibody were used to calculate the LTP content in Springcrest and Miraflores varieties of peach peel and pulp extracts. Purified LTP (2.5 mg/ml) was used to skin test 24 peach-sensitive patients. RESULTS: The purified LTP showed a single band at approximately 9 kDa. The polyclonal antibody raised anti LTP recognized only the LTP molecule in the peach extracts. LTP content, expressed in micro g/mg of freeze-dried extract in four extracts were: yellow peach peel, 15.48; yellow peach pulp 2.25; red peach peel 14.67 and red peach pulp 1.84. Twenty patients (83.3%) had a positive skin test with purified LTP. CONCLUSIONS: We have developed a system to determine the concentration of LTP in peach extracts. LTP in peel extracts is approximately seven times greater than in pulp.

Allergens↗

PubMed1997

Complement inactivation by allergenic plant pollen extracts.

Dialyzed aqueous extracts of plant pollen are widely used in the clinical practice of allergy for diagnostic and therapeutic purposes. The present investigation shows that such allergenic extracts are capable of consuming complement in every human serum, independent of the clinical condition. Complement is engaged by way of the first component C1, but without the participation of allergen-specific antibodies. The capacity of distinct pollen extracts to inactivate haemolytic complement was found to depend on the plant species, the most potent extracts being from the pollen of the weeds and trees. Analysis by UV-spectroscopy of the flavonoids remaining firmly bound to the proteins gives rise to the proposal that complement inactivation by allergenic and non-allergenic pollen extracts is due to polyphenolic (flavonoid) structures complexed with, or chemically conjugated to, the pollen proteins.

Allergens↗

PubMed1996

Extraordinary stability of IgE-binding Parietaria pollen allergens in relation to chemically bound flavonoids.

It is known that the skin-active and IgE-binding components in Parietaria pollen extracts are not restricted to the predominant protein allergens of M(r) 12000-15000, but are present as well among the naturally occurring constituents of M(r) < 10000. Indeed, the IgE-binding Parietaria pollen components are quite heterogeneous, ranging from high- to low-molecular mass, whereby the IgE-binding epitopes display an unusual chemical stability. Furthermore, the pollen of Parietaria species demonstrably contain a high proportion of flavonoid pigments. Since these pollen grains cannot be collected entirely free from non-pollen plant parts, the usual allergenic extracts of Parietaria encompass both the polyphenolic substrate molecules and the enzyme polyphenoloxidase as ingredients for the oxidative generation of flavonol-protein conjugates during the extraction process. In the present work this is illustrated by spectroscopic analyses of the free and bound flavonoids in Parietaria pollen extracts, as well as of the peptide fragments produced from the allergenic proteins by enzymatic or chemical hydrolysis. None of these relatively harsh treatments had a significant effect on the IgE-binding properties of the allergenic (sub-)components, even though detectable proteins in isoelectric focusing and immunoblotting were lost. It is proposed that the extraordinary stability of IgE-binding Parietaria components over a wide molecular range may be attributed to chromophoric flavonoid side-chains as (parts of) the corresponding B-cell epitopes.

Allergens↗

PubMed1994

Evaluation of the potency of allergenic extracts by inhibition of IgG-antibody binding.

A method is described for the in vitro potency evaluation of allergenic extracts by using their capacity of binding to specific human IgG antibodies. The results obtained with this inhibition-type enzyme immunoassay are compared with the analyses by the customary method of IgE antibody binding. A large series of allergenic protein fractions from the pollen of the Gramineae, Olea europea, Parietaria judaica, and from the dust mite Dermatophagoides pteronyssinus as well as from cat dander and peanuts were examined for inhibition of specific antibodies of both IgG and IgE isotypes. Potency evaluation by inhibition assays for IgE- and IgG-binding showed a significant correlation for the points of 50% inhibition (r = 0.92, p = 0.0001), but not for the slopes of the inhibition curves, i.e. the respective antibody avidities. Evidence is provided that the strict relationship between IgE- and IgG-inhibition by allergens could not be explained by possible cross-contaminations of the anti IgE- or anti IgG-reagents employed in the immunoassays. It is concluded that the inhibition of IgG-antibody binding presents a fast, reliable and low-cost alternative for the potency control of allergens used in clinical practice.

Allergens↗

PubMedDate not supplied

Investigation of acid phosphatase as a possible IgE-binding marker for pollen allergens and their polymerized derivatives.

The enzyme acid phosphatase represents an important component among the allergenic proteins in most pollen extracts. However, determination of the level of this enzyme in extracts of various pollen species, as well as protein separation by molecular sieving shows that acid phosphatase cannot be used as a marker for IgE-binding protein allergens. A conspicuous discrepancy was observed between the heat- and acid-sensitivities of the phosphatase enzyme relative to the overall IgE-binding properties of the pollen extracts. Remarkably, the enzyme remained unaffected by cross-linking the pollen proteins with glutardialdehyde, whereas this process of polymerization caused the IgE-binding potency to diminish considerably. It is concluded that the enzyme acid phosphatase is not a suitable marker for the potency assessment of pollen allergens, but may be useful for monitoring the production process of polymerized allergoids.

Acid Phosphatase↗