@article { ISI:000272903900005, title = {Differential elicitation of an aspartic protease inhibitor: regulation of endogenous protease and initial events in germination in seeds of vigna radiata}, journal = {Peptides}, volume = {30}, number = {12}, year = {2009}, month = {DEC}, pages = {2118-2126}, publisher = {ELSEVIER SCIENCE INC}, address = {360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA}, abstract = {

Plant aspartic proteases are of recent origin with their physiological significance in crucial processes emerging. Reports on the significance of aspartic protease inhibitors and their endogenous proteases in seeds of plants are scanty. This paper reports the purification of an aspartic protease inhibitor from the seeds of Vigna radiata, its control of the endogenous aspartic protease and their subsequent role in the early germination events. The role of the aspartic protease inhibitor and the enzyme in initial stages of germination of V. radiata has been tracked by differential timed expression and germination assays. The expression pattern revealed maximum expression of the inhibitor in the dormant seeds while the enzyme was predominant in the germinating seeds. Their expression patterns and interactions indicate their significance in initiation of germination. The expression of other classes of proteases was monitored during germination and a model predicting the events occurring during proteolysis of the storage protein in germination is hypothesized. The inhibitor was a linear, hydrophobic, pH stable and thermostable peptide with molecular weight of 1660 Da. The purified inhibitor showed a pI of 4.36 with the sequence as AEIYN KDGNK LDLYG. The inhibitor was found to be stable in a broad range of pH from 2 to 10 with an optimum of 3.0. The half-life of VrAPI at 100 degrees C was 30 min whereas the maximum activity was observed at 37 degrees C. The initial kinetic analysis of the inhibitor against the enclogenous protease showed an IC50 value of 11 nM while the value of the inhibition rate constant K-i was 34 x 10(-9) M. (C) 2009 Elsevier Inc. All rights reserved.

}, keywords = {Aspartic protease, Plant proteases, Protease inhibitors, Vigna radiata}, issn = {0196-9781}, doi = {10.1016/j.peptides.2009.08.024}, author = {Kulkarni, Aarohi and Rao, Mala} } @article { ISI:000296752300019, title = {Design, synthesis and biological evaluation of peptidyl-vinylaminophosphonates as novel cysteine protease inhibitors}, journal = {Bioorganic \& Medicinal Chemistry}, volume = {19}, number = {23}, year = {2011}, month = {DEC}, pages = {7129-7135}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

We report herein, design and synthesis of vinylaminophosphonates, a novel class of compounds as possible cysteine protease inhibitors. The synthesis of vinylaminophosphonates has been accomplished employing Tsuji-Trost reaction as a key step. The synthesized compounds were assayed against papain, a model cysteine protease and some of our synthesized compounds showed IC50 values in the range of 30-54 mu M thereby suggesting that these chemical entities thus could constitute an interesting template for the design of potential novel protease inhibitors. (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {Cysteine, Inhibitor design, Protease inhibitors, synthesis, Tsuji-Trost reaction, Vinylaminophosphonates}, issn = {0968-0896}, doi = {10.1016/j.bmc.2011.09.058}, author = {Bhattacharya, Asish K. and Rana, Kalpeshkumar C.} } @article { ISI:000305295000014, title = {Design, synthesis and evaluation of unique 2,4,5-triaryl imidazole derivatives as novel potent aspartic protease inhibitors}, journal = {Medicinal Chemistry}, volume = {8}, number = {3}, year = {2012}, month = {MAY}, pages = {428-435}, publisher = {BENTHAM SCIENCE PUBL LTD}, address = {EXECUTIVE STE Y-2, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATES}, abstract = {

The 2,4,5-triaryl imidazole derivatives (API) were designed, screened and characterized kinetically \& thermo-dynamically against Pepsin and their activity was also tested on the in silico platform. The docking studies of API with Pepsin show that these are novel and unique inhibitors of Aspartic protease. Drug like properties of these compounds were validated in silico based on Lipinski{\textquoteright}s rule of Five by calculating ClogP, LogS, H-bond acceptors, H-Bond donors, rotational bonds, PSA, PB and BBB values. The Et/Ki and Et/Km values of API show that they follow the Michaelis-Menten kinetics. The binding of inhibitors with proteases was explained by using Van{\textquoteright}t Hoff plot and thermodynamic parameters viz. free energy (Delta G), Entropy (Delta S) and Enthalpy (Delta H). The Van{\textquoteright}t Hoff analysis showed that the value of K-i decreases with increase in temperature and the binding of the inhibitor are entropically driven. API act as new potent aspartic protease inhibitors with K-i, for Pepsin, ranges from 3.7 mu M to 16.7 mu M. Strong hydrophobic groups at C-4 \& C-5 position in API favor binding of inhibitors with Pepsin. Experiments also showed that among C-2 aryl substituted imidazole, a 4-substitution on aryl ring is preferred and less polar substituent makes the molecule more active whereas polar substituents at 2-position on C-2 aryl ring makes the molecule less active. The docking studies of API with Pepsin further intensify and validate our results.

}, keywords = {2, 4, 5-triaryl imidazole derivatives, docking, Lipinski{\textquoteright}s rule of Five, Protease inhibitors, Thermodynamics}, issn = {1573-4064}, author = {Khan, Mohd Sajid and Akhtar, Salman and Siddiqui, S. A. and Siddiqui, M. S. and Srinivasan, K. V. and Arif, J. M.} } @article { ISI:000344440500015, title = {Identification and expression profiling of helicoverpa armigera microRNAs and their possible role in the regulation of digestive protease genes}, journal = {Insect Biochemistry and Molecular Biology}, volume = {54}, year = {2014}, month = {NOV}, pages = {129-137}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The present investigation is an effort to determine the possible roles of microRNAs (miRNAs) in the regulation of protease gene expression in Helicoverpa armigera upon exposure to plant protease inhibitors (PIs). Using Illumina platform, deep sequencing of 12 small RNA libraries was performed from H. armigera larvae fed on artificial diet (AD) or recombinant Capsicum annuum PI-7 (rCanPI-7) incorporated diet, at various time intervals (0.5, 2, 6, 12, 24, and 48 h). Sequencing data were analyzed with miRDeep2 software; a total of 186 unique miRNAs were identified from all the 12 libraries, out of which 96 were conserved while 90 were novel. These miRNAs showed all the conserved characteristics of insect miRNAs. Homology analysis revealed that most of the identified miRNAs were insect-specific, and more than 50 miRNAs were Lepidoptera-specific. Several candidate miRNAs (conserved and novel) were differentially expressed in rCanPI-7 fed larvae as compared to the larvae fed on AD. H. armigera miRNAs were found to have target sites in several protease genes as well as in protease regulation related genes such as serine PI and immune reactive PI. As expected, negative correlation in the relative abundance miRNAs and their target mRNAs was evident from qualitative real time polymerase chain reaction analysis. The investigation revealed potential roles of miRNAs in H. armigera protease gene regulation. (C) 2014 Elsevier Ltd. All rights reserved.

}, keywords = {Deep sequencing, Helicoverpa armigera, miRNAs, Protease gene regulation, Protease inhibitors}, issn = {0965-1748}, doi = {10.1016/j.ibmb.2014.09.008}, author = {Lomate, Purushottam R. and Mahajan, Neha S. and Kale, Sandip M. and Gupta, Vidya S. and Giri, Ashok P.} }