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It also records that phosphorylation does not change the potency of the drug, which matters for whether the loop blunts the drug.\nexposure: Protein kinase G or the catalytic subunit of protein kinase A with magnesium ATP and cyclic GMP\nevidence_span: {\"source_cache\": \"artifacts/sildenafil-research/10785399.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"d4048089a01ed860c8a71d096eb5bf1407e19557ca97c88b6cbac0e5f69de171\", \"start_char\": 0, \"end_char\": 2100, \"text_sha256\": \"d4048089a01ed860c8a71d096eb5bf1407e19557ca97c88b6cbac0e5f69de171\"}\n[sil-p10785399] Phosphorylation of phosphodiesterase-5 by cyclic nucleotide-dependent protein kinase alters its catalytic and allosteric cGMP-binding activities. 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