Search by BoMiProt ID - Bomi9

Primary Information

BoMiProt ID Bomi9
Protein Name Cathepsin B
Organism Bos taurus
Uniprot IDP07688
Milk FractionWhey
Ref Sequence ID NP_776456.1
Aminoacid Length 335
Molecular Weight 36661
FASTA Sequence Download
Gene Name CTSB
Gene ID 281105
Protein Existence Status Reviewed: Experimental evidence at protein level

Secondary Information

Presence in other biological fluids/tissue/cells lung secretions, liver, spleen, kidney, chorion,
Protein Function cysteine proteinase; degrades proteins such as caseins, insulin and collagen showing broad substrate specificity; exert an antihypertensive effect; has role in generation of thyroid hormones by proteolytic processing of thyroglobulin; role in calcium homeostasis; linked to neoplasia and metastasis; induces breakdown of cartilage proteoglycan. Cathepsin B is a cysteine-protease enzyme that plays significant role in metalloproteinase regulation. 
Biochemical Properties Endopeptidase; activated by DTT, optimum pH is 6; inactivated at pH above 7; broad substrate specificity; partially survived heat treatments; similar to chymosin in its cleavage sites; stable between pH 4.0 and pH 6.5, but it was very unstable at alkaline pH values. It was stable on heat treatment at 35 "C, 42 "C, and 47 "C for 15 min at pH 6.0; requires the presence of a sulfhydryl compound plus EDTA for maximal activity; inhibited by monoiodoacetate, microbial inhibitors such as leupeptin, chymostatin, and antipain, L-l-tosylamido- 2-phenylethylchloromethyl ketone, E-64
Significance in milk Cleaves ß and αS1 caseins; result in plasmin-like activity in high SCC milk and dairy products;
PTMs 111th Asn is glycosylated with high mannose type sugar
Site(s) of PTM(s)

N-glycosylation, O-glycosylation,
>sp|P07688|CATB_BOVIN Cathepsin B OS=Bos taurus OX=9913 GN=CTSB PE=1 SV=5
SCOP Class : Alpha and beta proteins (a+b)
Fold : Canonical type of Cysteine proteinases catalytic core
Superfamily : Cysteine proteinases
Family : Papain-like
Domain Name : 2DCC A:1-253

CATH Matched CATH superfamily
Predicted Disorder Regions NA
DisProt Annotation
TM Helix Prediction No TM helices
Significance of PTMs Mannose-6-phosphate-moities play a role as the targeting marker to the lysosomes
PDB ID 1ITO, 1QDQ, 1SP4, 2DC6, 2DC7, 2DC8, 2DC9, 2DCA, 2DCB, 2DCC, 2DCD,
Additional Comments Potentially influence the yield and quality of dairy products; significantly important in cancer therapy; inactivated aldolases (muscle and liver) and glucokinase as reported in rat liver; Amino acid analysis showed that crystalline cathepsin B contained hexosamine, and that the contents of glycine, aspartic acid, and glutamic acid are high and the content of methionine is low, as in cathepsin B from human liver
Bibliography 1. TOWATARI, T., KAWABATA, Y., & KATUNUMA, N. (1979). Crystallization and Properties of Cathepsin B from Rat Liver. European Journal of Biochemistry, 102(1), 279–289. >br/> 2. Berquin, I. M., Cao, L., Fong, D., & Sloane, B. F. (1995). Identification of two new exons and multiple transcription start points in the 5’-untranslated region of the human cathepsin-B-encoding gene. Gene, 159(2), 143–149.
3. Takio, K., Towatari, T., Katunuma, N., & Titani, K. (1980). Primary structure study of rat liver cathepsin B -----A striking resemblance to papain. Topics in Catalysis, 97(1), 340–346.
4. Burnett, D., Abrahamson, M., Devalia, J. L., Sapsford, R. J., Davies, R. J., & Buttle, D. J. (1995). Synthesis and secretion of procathepsin B and cystatin C by human bronchial epithelial cells in vitro: modulation of cathepsin B activity by neutrophil elastase. Archives of Biochemistry and Biophysics, 317(1), 305–310. 5.Akinyemi AO, Pereira GBS, Rocha FV. Role of Cathepsin B in Cancer Progression: A Potential Target for Coordination Compounds. Mini Rev Med Chem. 2021;21(13):1612-1624. doi: 10.2174/1389557521666210212152937. PMID: 33583372.