Analysis of casein alpha S1 & S2 proteins from different mammalian species

Abstract

Nowadays, the quality of any food used for human consumption is, to a considerable extent, considered by its possible contribution to the maintenance or improvement of the consumer's health. In developed countries there is increasing interest in goat milk and its derivates, the quality of which is considered of special importance in the light of current tendencies favouring healthy eating. In particular, goat's milk is a hypoallergenic alternative to cow's milk in the human diet. In the present work, we studied the casein alpha S1 and S2 proteins of cow, goat and sheep for comparative analysis. We found that the amino acid sequence of these proteins is almost same in goat and sheep but there are several changes at different base pairs when these two sequences are compared with cow. Prediction of secondary structures (GOR) was performed for alpha s1 and s2 proteins to gain functional insights. Our in silico study revealed considerable identity in chemical properties between goat and sheep but a considerable dissimilarity in cow with goat and sheep casein proteins. Moreover, the effect amino acid change on secondary structures in the three species is discussed. There was no significant difference found between goat and sheep alpha S1 and S2 proteins, so naturally both will be having same properties. The study concludes that sheep milk is another convenient alternative for the cow milk allergic children.

Sheep Milk: Physicochemical Characteristics and Relevance for Functional Food Development

“…Some children under 3 y old (0.3% to 7.5%) develop allergy against cow milk proteins (Spuergin and others 1997;Martín and others 2004;Masoodi and Shafi 2010;Viñas and others 2014;Gantner and others 2015). According to Masoodi and Shafi (2010), αS1 and αS2 protein sequences of goat and sheep have, at least, 99% similarity among themselves but the 2 differ markedly from the αS1 and αS2 protein sequence in cow. This fact suggests that sheep milk also promotes lower allergic sensitization.…”

“…This fact suggests that sheep milk also promotes lower allergic sensitization. Whey proteins also play an important role in people who are allergic to cow milk (Martín and others 2004;Masoodi and Shafi 2010). However, no data about allergenicity to sheep milk whey proteins are reported.…”

Investigating the genetic polymorphism of sheep milk proteins: a useful tool for dairy production

“…The nucleotide sequence of the genes ( CSN1S1 ) encoding for the α s1‐caseins in many eutherian species shows the presence of a highly conserved signal sequence of 15 residues but quite divergent sequences for the mature proteins suggesting that they are encoded by a rapidly evolving gene family. The α s1‐casein consists of 214 amino acids in each species . Bovine α s1‐casein exists in two phosphorylated forms containing eight and nine phosphates per mol .…”

“…The s1-casein consists of 214 amino acids in each species. 12 Bovine s1-casein exists in two phosphorylated forms containing eight and nine phosphates per mol. 13,14 Many s1-caseins variants have been described in domestic species.…”

Study of human allergic milk whey protein from different mammalian species using computational method

“…The ProtParam tool of ExPASy (http://www.expasy.ch/) was used to analyze amino acid and atomic composition [20]. Further isoelectric point, Extinction coefficient and hydropathicitywas observed and compared between four species.Secondary structure prediction was done using SABLE (http://www.sable.cchmc.org) of obtained sequence in dataset.…”