Search by BoMiProt ID - Bomi103

Primary Information

BoMiProt ID Bomi103
Protein Name Alpha-S1-casein
Organism Bos taurus
Uniprot IdP02662
Milk FractionWhey
Ref Sequence Id NP_851372.1
Amino Acid Lenth 214
Molecular Weight 24529
Fasta Sequence
Gene Name CSN1S1
Gene Id 282208
Protein Existence Status Reviewed: Experimental evidence at protein level

Secondry Information

Endogenous/Bioactive peptides - Fragment - Sequence - Effect α-casein exorphin - 90–96 - RYLGYLE - Opioid Ref
α-casein exorphin - 90–95 - RYLGYL Opioid Ref
α-casein exorphin - 91–96 - YLGYLE - Opioid Ref
s1-Casokinin-5 - 23–27 - FFWAP - ACE inhibition Ref
s1-Casokinin-7 - 28–34 - FPEWFGK - ACE inhibition Ref
s1-Casokinin-6 -194–199 - TTMPLW - ACE inhibition, Immunomodulatory Ref
Protein Function A major allergen
Biochemical Properties acidic protein; isoelectric point 4.1-4.5; 17 proline residues, uniformly distributed over the molecule, and a high content (45%) of hydrophobic residues; random coil conformation; stabilized by hydrophobic interactions; contains sequential epitopes and only a few conformational epitopes
Significance in milk found to enhance calcium absorption resulted in the production of greater bone mass and correspondingly increased resistance to bone fracture in the rat femurs
PTMs Phosphoprotein; nine phosphorylated serine residues and a highly negatively charged region including residues 41-77
Site(s) of PTM(s)

N-glycosylation, O-glycosylation,
>sp|P02662|CASA1_BOVIN Alpha-S1-casein OS=Bos taurus OX=9913 GN=CSN1S1 PE=1 SV=2
Bibliography 1. Spuergin, P., Mueller, H., Walter, M., Schiltz, E., & Forster, J. (1996). Allergenic epitopes of bovine alpha S1-casein recognized by human IgE and IgG. Allergy, 51(5), 306–312.
2. Masoodi, T. A., & Shafi, G. (2010). Analysis of casein alpha S1 & S2 proteins from different mammalian species. Bioinformation, 4(9), 430.
3. Farrell, H. M., Malin, E. L., Brown, E. M., & Mora-Gutierrez, A. (2009). Review of the chemistry of αS2-casein and the generation of a homologous molecular model to explain its properties. Journal of Dairy Science, 92(4), 1338–1353.
4. Minervini F, Algaron F, Rizzello CG, Fox PF, Monnet V, Gobbetti M. Angiotensin I-converting-enzyme-inhibitory and antibacterial peptides from Lactobacillus helveticus PR4 proteinase-hydrolyzed caseins of milk from six species. Appl Environ Microbiol [Internet]. 2003 Sep [cited 2019 Nov 26];69(9):5297–305. Available from:
5. Hideaki K, Kunio D, Shigeru S, Hideyo U, Ryuji S, Umeji M, et al. Antihypertensive effect of tryptic hydrolysate of milk casein in spontaneously hypertensive rats. Comp Biochem Physiol Part C, Comp. 1990;96(2):367–71.
6. Loukas S, Varoucha D, Zioudrou C, Streaty RA, Klee WA. Opioid Activities and Structures of α-Casein-Derived Exorphins. Biochemistry. 1983;22(19):4567–73.
7. Maruyama S, Suzuki H. Agricultural and Biological Chemistry A Peptide Inhibitor of Angiotensin I Converting Enzyme in the Tryptic Hydrolysate of Casein. 2014 [cited 2019 Nov 26]; Available from: