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Primary structure of human urinary prokallikrein
S Takahashi1, A Irie, Y Miyake
1Department of Biochemistry, National Cardiovascular Center Research Institute, Osaka, Japan.
Journal of Biochemistry
|July 1, 1988
Summary
The complete amino acid sequence of human urinary prokallikrein was determined, revealing its structure and tissue-specific excretion. This finding clarifies the protein
Area of Science:
- Biochemistry
- Molecular Biology
- Proteomics
Background:
- Human urinary prokallikrein is a precursor to kallikrein, an enzyme involved in various physiological processes.
- Understanding the primary structure of prokallikrein is crucial for elucidating its function and potential therapeutic applications.
Purpose of the Study:
- To determine the complete amino acid sequence of human urinary prokallikrein.
- To compare its structure with kallikrein and related proteins.
- To investigate its tissue-specific nature and excretion pathway.
Main Methods:
- Amino acid analysis and peptide fragment sequencing.
- Chemical and enzymological cleavage of kallikrein.
- N-terminal sequence comparison between prokallikrein and kallikrein.
Main Results:
- The complete amino acid sequence of human urinary prokallikrein was elucidated, comprising 238 residues of kallikrein and 7 propeptide residues.
- Identified three common glycosylation sites (Asn-X-Thr/Ser) and two trypsin-susceptible sites.
- Confirmed identity with human pancreatic and kidney kallikreins and homology with animal kallikreins.
- Key catalytic and specificity-determining amino acid residues are conserved.
Conclusions:
- Human urinary prokallikrein is a tissue-specific protein.
- It is excreted in urine without modification.
- The determined sequence provides insights into kallikrein function and evolution.