Abstract
The processing of proinsulin is being used in our laboratory to examine the selectivity demonstrated by propeptide converting enzymes. PC1 is responsible for the cleavage of the B-chain/Cpeptide junction in proinsulin. We have recently succeeded in generating recombinant human proinsulin (hPI) from bacteria, and PC1 using a baculovirus system. We have also developed an in vitro assay and are now attempting to determine kinetic constants for the action of a converting enzyme with its authentic substrate. Our initial results indicate that the Km for hPI is approximately 2 iiM compared to 25 nM for Pyr-RTKR-AMC. In the absence of an active site directed probe, RIA determination of enzyme concentration provides a lower limit for /tcat of 1 s-' for hPI and 0.5 S'1 for PyrRTKR-AMC. From this, the ratios of the specificity constants C
| Original language | English |
|---|---|
| Journal | FASEB Journal |
| Volume | 11 |
| Issue number | 9 |
| State | Published - 1997 |
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All Science Journal Classification (ASJC) codes
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Cell Biology
Cite this
The propeptide converting enzyme PC1 prefers proinsulin over fluorescent peptide analogs as its substrate. / Mackin, Robert.
In: FASEB Journal, Vol. 11, No. 9, 1997.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The propeptide converting enzyme PC1 prefers proinsulin over fluorescent peptide analogs as its substrate
AU - Mackin, Robert
PY - 1997
Y1 - 1997
N2 - The processing of proinsulin is being used in our laboratory to examine the selectivity demonstrated by propeptide converting enzymes. PC1 is responsible for the cleavage of the B-chain/Cpeptide junction in proinsulin. We have recently succeeded in generating recombinant human proinsulin (hPI) from bacteria, and PC1 using a baculovirus system. We have also developed an in vitro assay and are now attempting to determine kinetic constants for the action of a converting enzyme with its authentic substrate. Our initial results indicate that the Km for hPI is approximately 2 iiM compared to 25 nM for Pyr-RTKR-AMC. In the absence of an active site directed probe, RIA determination of enzyme concentration provides a lower limit for /tcat of 1 s-' for hPI and 0.5 S'1 for PyrRTKR-AMC. From this, the ratios of the specificity constants C
AB - The processing of proinsulin is being used in our laboratory to examine the selectivity demonstrated by propeptide converting enzymes. PC1 is responsible for the cleavage of the B-chain/Cpeptide junction in proinsulin. We have recently succeeded in generating recombinant human proinsulin (hPI) from bacteria, and PC1 using a baculovirus system. We have also developed an in vitro assay and are now attempting to determine kinetic constants for the action of a converting enzyme with its authentic substrate. Our initial results indicate that the Km for hPI is approximately 2 iiM compared to 25 nM for Pyr-RTKR-AMC. In the absence of an active site directed probe, RIA determination of enzyme concentration provides a lower limit for /tcat of 1 s-' for hPI and 0.5 S'1 for PyrRTKR-AMC. From this, the ratios of the specificity constants C
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M3 - Article
VL - 11
JO - FASEB Journal
JF - FASEB Journal
SN - 0892-6638
IS - 9
ER -