Primary Information
BoMiProt ID	Bomi98
Protein Name	Alpha-lactalbumin
Organism	Bos taurus
Uniprot ID	P00711
Milk Fraction	Whey
Ref Sequence ID	NP_776803.1
Aminoacid Length	142
Molecular Weight	16247
FASTA Sequence	Download
Gene Name	LALBA
Gene ID	281894
Protein Existence Status	Reviewed: Experimental evidence at protein level
Secondary Information
Endogenous/Bioactive peptides - Fragment - Sequence - Effect	Lactorphines - 50–53 - YGLF - Opioid agonist ACE inhibition Ref Lactokinins - ACE inhibitory Ref
Protein Function	Inhibits the formation of N-acetyllactosamine; reduction of stress; antimicrobial activity; opioid activity; antihypertensive action; regulation of cells growth; antiulcer activity and immunomodulation;
Biochemical Properties	acidic, compact globular structure stabilized by four disulfide bonds; metalloprotein with a single Ca2+ binding site; isoelectric point of 4.6; has no free thiol groups; genetically and structurally homologous to c-type lysozyme; has two predominant genetic variants (A and B); The B variant is present in the milk of most Bos taurus cattle, and both the A and B variants are found in the milk of Bos indicus cattle; Both A and B variant contain four disulfide bonds and no phosphate groups; the tertiary structure of LA is composed of a large domain (α) with pH stable α helices and a small domain (β) divided by a cleft; partially folded intermediate states; acidic pH and in the apo-state at elevated temperatures LA is the classic molten globule which is highly stable; Calcium binding strongly influences the molecular stability of LA and is required for refolding and native disulfide bond formation in the reduced, denatured protein; Removal of Ca2+ from the protein enhances its sensitivity to pH and ionic conditions due to noncompensated negative charge-charge interactions at the cation binding site, which significantly reduces its overall stability; At neutral pH and low ionic strength, the native structure of apo-LA is stable below 140C and undergoes a conformational change to a native-like molten globule intermediate at temperatures above 250C; difficult to hydrolyse; highly resistant to tryptic digestion
Significance in milk	LA has a high content of lysine and cysteine and a particularly high content of tryptophan; between bovine and human milks are the lower concentrations of tryptophan and cysteine in the latter; a critical factor in the nutrition of neonates in general and premature neonates; The high content of cysteine in LA is also valuable in boosting the immune system and promoting wound healing. LA also has a high level of tryptophan, which may help improve mood, sleep and cognitive performance;
PTMs	A small percentage of the LA found in the milk of cattle is glycosylated on an Asn residue; presence of neutral sugars such as mannose, galactose and fucose, aminosugars such as glucosamine and galactosamine, presence of N-Acetylneuraminic acid and N-Glyeolloylneuraminic acid
Site(s) of PTM(s) N-glycosylation, O-glycosylation, Phosphorylation	>sp|P00711|LALBA_BOVIN Alpha-lactalbumin OS=Bos taurus OX=9913 GN=LALBA PE=1 SV=2 MMSFVSLLLVGILFHATQAEQLTKCEVFRELKDLKGYGGVSLPEWVCTTF HTSGYDTQAIVQNN*64DSTEYGLFQINNKIWCKDDQNPHSSNICNISCDKFL DDDLTDDIMCVKKILDKVGINYWLAHKALCSEKLDQWLCEKL
SCOP	Class : Alpha and beta proteins (a+b) Fold : Lysozyme-like Superfamily : Lysozyme-like Family : C-type lysozyme Domain Name : 1F6S A:1-122
CATH	Matched CATH superfamily 1.10.530.10
Predicted Disorder Regions	NA
DisProt Annotation
TM Helix Prediction	No TM helices
PDB ID	1F6R, 1F6S, 1HFZ, 2G4N, 6IP9,
Bibliography	1. Barman, T. E. (1970). Purification and properties of bovine milk glyco-alpha-lactalbumin. Biochimica et Biophysica Acta, 214(1), 242–244. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/5488946. 2. Universitatea Dunărea de Jos Galați. (n.d.). The Annals of the University Dunarea de Jos of Galati. Fascicle VI, Food technology. Retrieved from http://agris.fao.org/agris-search/search.do?recordID=DJ2012060152. 3. Permyakov, E. A., Shnyrov, V. L., Kalinichenko, L. P., Kuchar, A., Reyzer, I. L., & Berliner, L. J. (1991). Binding of Zn(II) ions to alpha-lactalbumin. Journal of Protein Chemistry, 10(6), 577–584. https://doi.org/10.1007/bf01025709. 4. Ghosh, B. C., Prasad, L. N., & Saha, N. P. (2017). Enzymatic hydrolysis of whey and its analysis. Journal of Food Science and Technology, 54(6), 1476–1483. https://doi.org/10.1007/s13197-017-2574-z. 5. Sitohy, M., Chobert, J. M., & Haertlé, T. (2001). Susceptibility to trypsinolysis of esterified milk proteins. International Journal of Biological Macromolecules, 28(4), 263–271. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/11311716. 6. Sternhagen, L. G., & Allen, J. C. (2001). Growth rates of a human colon adenocarcinoma cell line are regulated by the milk protein alpha-lactalbumin. Advances in Experimental Medicine and Biology, 501, 115–120. https://doi.org/10.1007/978-1-4615-1371-1_14. 7. Svensson, M., Håkansson, A., Mossberg, A. K., Linse, S., & Svanborg, C. (2000). Conversion of alpha-lactalbumin to a protein inducing apoptosis. Proceedings of the National Academy of Sciences of the United States of America, 97(8), 4221–4226. https://doi.org/10.1073/pnas.97.8.4221. 8. Yamaguchi, M., & Uchida, M. (2007). Alpha-lactalbumin suppresses interleukin-6 release after intestinal ischemia/reperfusion via nitric oxide in rats. Inflammopharmacology, 15(1), 43–47. https://doi.org/10.1007/s10787-006-1558-9.