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Penta-L-lysine Potentiates Fibrin-Independent Activity of Human Tissue Plasminogen Activator.

DIR@IMTECH: CSIR-Institute of Microbial Technology

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Title Penta-L-lysine Potentiates Fibrin-Independent Activity of Human Tissue Plasminogen Activator.
 
Creator Rehan, Mohammad
Sagar, Amin
Sharma, Vandna
Mishra, Sanskruti
Ganguly, Ashish
Sahni, Girish
 
Subject QR Microbiology
 
Description The therapeutic action of tissue plasminogen activator (t-PA) is a two-step process: (1) binding to lysine-rich fibrin (Km event) and (2) converting local plasminogen into plasmin (Kcat event). Overcoming limitations of other structural biophysics methods, we wanted to employ small-angle X-ray scattering (SAXS) to visualize what shape changes occur/accompany t-PA activation, but the prime hurdle was the polydisperse nature of the fibrin, which occluded scattering information from t-PA. Earlier, larger polylysine peptides have been used to potentiate activation of t-PA, so while screening short polylysine peptides as alternatives to fibrin or larger peptides, we found that penta-polylysine (P5) specifically activates t-PA in a dose-dependent manner, averaging to almost 3-fold more than in the absence of any peptide. SAXS data analysis confirmed that P5 does not induce association of t-PA molecules, and a narrower peak profile of the Kratky plot indicated that P5 binding quenches inherent motion in t-PA. Shape reconstruction of t-PA ∓ P5 revealed that P5 closes the "gap" between the two gross domains of t-PA, viz. fused F/E, K1 and K2 domains, and the P domain. Docking experiments suggested that, while other polylysine peptides preferentially interacted with the surfaces of kringle domains, P5 "slipped into" the gap/groove between K2 and P domains, thereby mediating a substantial increase in the number of long-range interactions between the K2 domain and exosites in the P domain. We report here dissection of shape events involved in between Km/Kcat steps of t-PA activation, which can pave the way toward the search for small molecule function regulator(s) of t-PA.
 
Publisher ACS Publications
 
Date 2015-10-22
 
Type Article
PeerReviewed
 
Relation http://pubs.acs.org/doi/10.1021/acs.jpcb.5b07735
http://crdd.osdd.net/open/1749/
 
Identifier Rehan, Mohammad and Sagar, Amin and Sharma, Vandna and Mishra, Sanskruti and Ganguly, Ashish and Sahni, Girish (2015) Penta-L-lysine Potentiates Fibrin-Independent Activity of Human Tissue Plasminogen Activator. The journal of physical chemistry. B, 119 (42). pp. 13271-7. ISSN 1520-5207