Cyclophilin H (also known as peptidylpropyl isomerase H, PPIH) is a member of peptidyl-propyl cis-trans isomerase (PPIase) family, which catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerates the folding of proteins. The cyclophilin H is a specific component of the human U4/U6 small nuclear ribonucleoprotein particle involved in the nuclear splicing of pre-mRNA. It stably associates with the U4/U6-60kD and - 90kD proteins, the human orthologues of the Saccharomyces cerevisiae Prp4 and Prp3 splicing factors. Source: Recombinant protein corresponding to aa1-177 from human Cyclophilin H, expressed in E. coli. Molecular Weight: ~19.2kD (177aa) Specific Activity: >220 nmoles/min/mg, and is defined as the amount of enzyme that cleaves 1umole of suc-AAFP-pNA/minute at 25C in Tris-Hcl, pH 8.0, using chymotrypsin. Activity Assay: 1. Prepare 170ul assay buffer into a suitable container and pre-chill on ice before use: The final concentrations are 200mM Tris-Hcl, pH 8.0, and 20nM chymotrypsin. 2. Add 10ul of recombinant Cyclophikin H (PPIH) protein with 1ug in assay buffer. 3. Mix by inversion and equilibrate to 1C and monitor the A405nm until the value is constant using a spectrophotometer. 4. Add 20ul pre-chilled 5mM suc-AAFP-pNA. (Substrate was dissolved in TFE that contained 460mM LiCl to a concentration of 3mM) 5. Record the increase in A405 nm for 30 minutes at 25C. Amino Acid Sequence: MAVANSSPVN PVVFFDVSIG GQEVGRMKIE LFADVVPKTA ENFRQFCTGE FRKDGVPIGY KGSTFHRVIK DFMIQGGDFV NGDGTGVASI YRGPFADENF KLRHSAPGLL SMANSGPSTN GCQFFITCSK CDWLDGKHVV FGKIIDGLLV MRKIENVPTG PNNKPKLPVV ISQCGEM Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing.. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
