BPTI Library Construction

Creative Biolabs offers the unique BPTI phage display library construction service for our customers all over the world. Our scientists are confidence in generating high quality BPTI library with high affinity and diversity.

Bovine pancreatic trypsin inhibitor (BPTI), which is also known as aprotinin and Trasylol, is a small monomeric (single-chain) globular polypeptide of molecular weight 6512. It is derived from bovine lung tissue and the classic member of Kunitz family protease inhibitors. Structure analysis indicates BPTI consists of three disulfide bonds, a C-terminal α-helix and a twisted β-hairpin. There are 16 different amino acid types arranged in a chain of 58 residues that folds into a compact and stable tertiary structure that categorized as "small SS-rich". The high stability of BPTI molecule is owed to the three disulfide bonds linking the six cysteine members of the chain. The exposed loop of BPTI, which constructs by basic lysine 15 side chain, can tightly binding the specificity pocket of trypsin active site, then inhibit its enzymatic action.

BPTI is an anti-fibrinolytic molecule that inhibits several serine proteases, in particular trypsin, chymotrypsin and plasmin. BPTI action on plasmin independently slows fibrinolysis. The action on kallikrein results in inhibition of factor XIIa formation. Then, both the intrinsic pathway of fibrinolysis and coagulation are inhibited. BPTI has been used as an injection medication that reduces bleeding during complex surgery, such as liver and heart surgery. Its main effect is the deceleration of fibrinolysis, the process that results in the breakdown of blood clots. In this way, BPTI can be chosen as a potential scaffold for specific serine proteases or other relevant targets.

Scientists of Creative Biolabs adopt the improved Hi-Affi™ phage display platform which can achieve high affinity and diversity library construction. This platform based on phage display technology, which is an exogenous gene expression method through fusing the target genes to bacteriophage coat proteins then displaying on the phage surfaces to select specific binders. Moreover, the trimer codon technology and NNK method are also coalesced into this platform, which endow more randomicity and affinity of generated libraries. Hi-Affi™ phage display platform is ideal for sorting and isolating the high affinity protein or peptide targets. With this outstanding platform, our scientists can ensure the generated BPTI phage display library to achieve 100% precise mutant and over 1010 diversity.

With years of research and develop experience in scaffold protein library construction, Creative Biolabs has become an expert in this field. We commit to provide the best library construction service with reasonable price for our global customers. Up to now, our professional scientists have generated about 55 kinds of scaffold libraries for our global customers and are able to meet each specific requirement for clients’ satisfaction.

BPTI Library Construction
Fig. 1 A simplified BPTI variant stabilized by the A14G and A38V substitutions. (PDB ID: 3AUB)

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