Polymorphism at donkey ß-lactoglobulin II locus: identification and characterization of a new genetic variant with a very low expression.
Amino Acids
; 50(6): 735-746, 2018 Jun.
Article
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| MEDLINE
| ID: mdl-29572574
ABSTRACT
In the last years, donkey milk had evidenced a renewed interest as a potential functional food and a breast milk substitute. In this light, the study of the protein composition assumes an important role. In particular, ß-lactoglobulin (ß-LG), which is considered as one of the main allergenic milk protein, in donkey species consists of two molecular forms, namely ß-LG I and ß-LG II. In the present research, a genetic analysis coupled with a proteomic approach showed the presence of a new allele, here named F, which is apparently associated with a null or a severely reduced expression of ß-LG II protein. The new ß-LG II F genetic variant shows a theoretical average mass (Mav) of 18,310.64 Da, a value practically corresponding with that of the variant D (∆mass < 0.07 Da), but differs from ß-LG II D for two amino acid substitutions Thr100 (variant F) â Ala100 (variant D) and Thr118 (variant F) â Met118 (variant D). Proteomic investigation of the whey protein fraction of an individual milk sample, homozygous FF at ß-LG II locus, allowed to identify, as very minor component, the new ß-LG II F genetic variant. By MS/MS analysis of enzymatic digests, the sequence of the ß-LG II F was characterized, and the predicted genomic data confirmed.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Variación Genética
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Regulación de la Expresión Génica
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Equidae
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Sitios Genéticos
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Lactoglobulinas
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
Amino Acids
Asunto de la revista:
BIOQUIMICA
Año:
2018
Tipo del documento:
Article
País de afiliación:
Italia