Improving the Specificity of the Prostate‐Specific Antigen Substrate Glutaryl‐Hyp‐Ala‐Ser‐Chg‐Gln as a Promoiety. (9th April 2015)

• Record Type: Journal Article
• Authors: Aloysius, Herve; Hu, Longqin
• Is Part Of: Chemical biology & drug design. Volume 86:Number 4(2015:Oct.)
• Page Start: 837
• Page End: 848
• Publication Date: 2015-04-09
• Subjects: Drugs -- Design -- Periodicals; Pharmaceutical chemistry -- Periodicals; Biochemistry -- Periodicals; 615.19005
• DOI: 10.1111/cbdd.12559
• Languages: English
• ISSNs: 1747-0277

Abstract

<abstract abstract-type="main" id="cbdd12559-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>To develop PSA peptide substrates with improved specificity and plasma stability from the known substrate sequence glutaryl‐Hyp‐Ala‐Ser‐Chg‐Gln, systematic replacements of the <italic>N</italic>‐terminal segment with D‐retro‐inverso‐peptides were performed with the incorporation of 7‐amino‐4‐methylcoumarin (7‐AMC) after Gln for convenient fluorometric determination and ranking of the PSA substrate activity. The D‐retro‐inverso‐peptide conjugates with P2‐P5 D‐amino acid substitutions were moderate but poorer PSA substrates as compared to the original peptide, suggesting that inversion of the amide bonds and/or incorporation of the additional atom as in the urea linker adversely affected PSA binding. However, P5 substitution of Hyp with Ser showed significant improvements in PSA cleavage rate; the resulting AMC conjugate, glutaryl‐Ser‐Ala‐Ser‐Chg‐Gln‐AMC (<bold>11</bold>), exhibited the fastest PSA cleavage rate of 351 pmol/min/100 nmol PSA. In addition, GABA←mGly‐Ala‐Ser‐Chg‐Gln‐AMC (conjugate <bold>6</bold>) was the second best PSA substrate and released 7‐AMC at a rate of 225 pmol/min/100 nmol PSA as compared to 171 pmol/min/100 nmol PSA for the control conjugate glutaryl‐Hyp‐Ala‐Ser‐Chg‐Gln‐AMC. Incubations of selected AMC conjugates with mouse and human plasma revealed that GABA←D‐Ser‐<italic>ψ</italic>[NH‐CO‐NH]‐Ala‐Ser‐Chg‐Gln‐AMC (<bold>5</bold>) and GABA←mGly‐Ala‐Ser‐Chg‐Gln‐AMC (<bold>6</bold>) were most stable to non‐PSA‐mediated proteolysis. Our results suggest that the PSA specificity of glutaryl‐Hyp‐Ala‐Ser‐Chg‐Gln is improved with Ser and mGly substitutions of Hyp at the P5.</p> </abstract>