Protocol Online logo
Top : Forum Archives: : Protein and Proteomics

protein expression - pkk223-3 vector (Feb/24/2005 )

Hi all,
i've cloned my gene in pUC19 and expreesed protein in JM109, but i'm getting very low activity for this enzyme, according to one former lab member, she had the same problem and when she subcloned this gene into pKK223-3 and expressed in JM101 , she could get much better activity. So now i've to subclone it too, could anyone suggest me from where to get pkk 223-3 sold by pharmacia, but i searched and could not find where to order from, all help is greatly appreciated.


If you are interested in large amounts of expressed protein, then you have to go for the best expression systems. Subclone the gene into a suitable pET vector and express in BL 21 host. Both are available with Stratagene.

good luck

Natioanl Chemical Laboratory,



it seems that pkk 233-3 is from pl pharmacia, private enterprise. Here can you find their phone and some features...


Addtional :
pub med entry

sequence :


thanx for those inputs but problem is pharamacia stopped selling this vector long time back and i couldn't find it with anyone here. could someone tell me if its a low copy # vector or how it differs from pUC19, or if someone could suggest similar vector. why i want to subclone in this vector is cause i don't want high/rapid expression system like BL21.