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Combining proteomic tools to characterize the protein fraction of llama ( Lama glama ) milk
Author(s) -
Saadaoui Besma,
Bianchi Leonardo,
Henry Céline,
Miranda Guy,
Martin Patrice,
Cebo Christelle
Publication year - 2014
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201300383
Subject(s) - biology , lactalbumin , skimmed milk , lactoferrin , alpha lactalbumin , albumin , whey protein , food science , chromatography , chemistry , biochemistry
Llamas belong to the Camelidae family along with camels. While dromedary camel milk has been broadly characterized, data on llama milk proteins are scarce. The objective of this study was thus to investigate the protein composition of llama milk. Skimmed llama milk proteins were first characterized by a 2D separation technique coupling RP‐HPLC in the first dimension with SDS‐PAGE in the second dimension (RP‐HPLC/SDS‐PAGE). Llama milk proteins, namely caseins (α s1 ‐, α s2 ‐, β‐, and κ‐caseins), α‑lactalbumin, lactoferrin, and serum albumin, were identified using PMF. Llama milk proteins were also characterized by online LC‐ESI‐MS analysis. This approach allowed attributing precise molecular masses for most of the previously MS‐identified llama milk proteins. Interestingly, α‐lactalbumin exhibits distinct chromatographic behaviors between llama and dromedary camel milk. De novo sequencing of the llama α‐lactalbumin protein by LC coupled with MS/MS (LC‐MS/MS) showed the occurrence of two amino acid substitutions (R62L/I and K89L/I) that partly explained the higher hydrophobicity of llama α‐lactalbumin compared with its dromedary counterpart. Taken together, these results provide for the first time a thorough description of the protein fraction of Lama glama milk.