|Datasheet||Specific References||Reviews||Related Products||Protocols|
|Human Cell lysate that Human CST1 / Cystatin-1 / Cystatin-SN transfected / overexpressed for Western blot (WB) positive control. The whole cell lysate is provided in 1X Sample Buffer (1X modified RIPA buffer+1X SDS loading buffer).|
|A DNA sequence encoding the human CST1 (P01037-1) (Met 1-Ser 141) was fused with a polyhistidine tag at the C-terminus.|
|The secreted recombinant human CST1 consists of 132 amino acids and has a calculated molecular mass of 15.6 kDa. It migrates as an approximately 17 kDa band in SDS-PAGE under reducing conditions as predicted.|
|Cell lysate was prepared by homogenization in ice-cold modified RIPA Lysis Buffer with cocktail of protease inhibitors (Sigma). Cell debris was removed by centrifugation. Protein concentration was determined by Bradford assay (Bio-Rad protein assay, Microplate Standard assay). The cell lysate was boiled for 5 min in 1 x SDS loading buffer (50 mM Tris-HCl pH 6.8, 12.5% glycerol, 1% sodium dodecylsulfate, 0.01% bromophenol blue) containing 5% b-mercaptoethanol, and lyophilized.|
|Modified RIPA Lysis Buffer: 50 mM Tris-HCl pH 7.4, 150 mM NaCl, 1mM EDTA, 1% Triton X-100, 0.1% SDS, 1% Sodium deoxycholate, 1mM PMSF.|
|12.5% SDS-PAGE Stained with Coomassie Blue after protein purification.|
|Samples are stable for up to twelve months from date of receipt.|
|1. Centrifuge the tube for a few seconds and ensure the pellet at the bottom of the tube. 2. Re-dissolve the pellet using 200μL pure water and boil for 2-5 min. 3. Store the lyophilized cell lysate at 4℃. After re-dissolution, recommend to aliquot it into smaller quantities and store at -80℃.|
|1 X Sample Buffer (1 X modified RIPA buffer+1 X SDS loading buffer).|
|Store at 4℃. After re-dissolution, aliquot and store at -80℃.|
|Western blot (WB): Use at an assay dependent dilution.|
Other Applications: Not tested.
Optimal dilutions/concentrations should be determined by the end user.
Cystatin-SN, also known as Cystain-SA-I, Cystatin-1, Salivary cystatin-SA-1 and CST1, is a secreted protein which belongs to the cystatin family. The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. Cystatin-SN / CST1 is expressed in submandibular and sublingual saliva but not in parotid saliva (at protein level). Cystatin-SN / CST1 is also expressed in saliva, tears, urine and seminal fluid. Human saliva appears to contain several cysteine proteinase inhibitors that are immunologically related to cystatin S but that differ in their specificity due to amino acid sequence differences. Human salivary cystatins include Cystatin-S, Cystatin-S1, Cystatin-S2, Cystatin- SA, Cystatin-SN, Cystatin-C and Cystatin-D. Cystatin-SN is a much better inhibitor of papain and dipeptidyl peptidase I than is cystatin-S, although both inhibit ficin equally well.