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Drug Development Diagnostics & Biotechnology Division

Dr. Anil K. Ghosh

Scientist G
PhD, Calcutta University, 1980
Contact: aghosh@iicb.res.in

Current Research Interest

Trehalose metabolism in yeast:

Trehalose is a non reducing disaccharide found in a wide variety of organisms including bacteria, yeast, fungi, insects, plants etc. Trehalose acts as a source of energy and carbon in the organisms. It is also a very well known anti stress sugar, it’s accumulation by different organisms is being recognized as a crucial defense mechanism that stabilizes proteins and biological membranes under a variety of stress conditions, including increased temperature, hydrostatic pressure, desiccation, nutrient starvation, oxidative stress, and even exposure to toxic chemicals. In some organisms, like yeast and plants, it may also serve as a signaling molecule to direct or control certain metabolic pathways or even to affect growth. From our lab novel types of trehalose utilization and hydrolyzing enzymes in Saccharomyces cerevisiae was identified. The synthesizing enzymes trehalose-6-phosphate synthase and trehalose-6-phosphate phosphatase and the hydrolyzing enzyme acid trehalse from S. cerevisiae have been purified to the stage of electrophoretic homogeneity. The substrate specificity of the enzyme as well as regulation by methylation has already been investigated. Trehalose metabolism in Candida utilis is also under investigation. Isolation, purification, biochemical characterization and regulation of the enzymes involved in trehalose metabolism are under way.

 

Deamidation mediated inactivation and role of Isoaspartyl methyl Transferase towards the reactivation of protein

Most prevalent pathways for inactivation of enzyme protein under physiological stress(like pH, temp, oxidative stress etc) are deamidation and isomerization at asparaginyl and aspartyl residues, leading to the formation of L-aspartate, L-isoaspartate, and D-aspartate residues in the polypeptide backbone and thus three dimensional structures as well as biological activity is altered. Transpeptidylated proteins are reported to increase aggregation property.

 

Pathways for spontaneous deamidation and isomerization for aspartyl and asparaginyl hexapeptides.

Protein Isoaspartyl Methyl Transferase (PIMT) catalyses the transfer of methyl group from AdoMet to iso-aspartyl residues of peptides or proteins and initiates their conversion back into the normal L-aspartate form by a methyl esterification reaction. PIMT is widely found in bacteria, plants, nematodes, flies, and mammals, including humans, and displays a high degree of sequence conservation.

Methylation of L-isoaspartyl residues by protein isoaspartyl-methyl transferase (PIMT), facilitating reformation of the succinimide intermediate; hydrolysis produces either L-aspartate (REPAIRED PROTEIN) or L-isoaspartate. The methyl donor is S-adenosyl-L-methionine (AdoMet), converted to S-adenosylhomocysteine (AdoHcy) by catalysis. The peptide backbone is shown as the heavy and dotted lines.

Our lab is currently focusing on purification and biochemical characterization of PIMT from various organisms as well as investigating the correlation between deactivation of enzyme proteins under physiological stress and amount of deamidation and isomerisation in those enzyme proteins. Ability of PIMT towards reactivation of the deamidated enzymes is also under investigation.

Names of the group members including regular staff with designation and research fellows:
Staff: Fellow/RA Others 

Dr. Ramadhan Majhi, TO 

[ rmajhi2007@rediffmail.com]
  1. Mrs. Shinjinee Sengupta (SRF) [Shin143@gmail.com]
  2. Mr. Sagar Lahiri (PA II) [sagar_rs@iicb.res.in]
  3. Ms. Shakri Banerjee (PA II) [shakribanerjee@gmail.com]

Mr. Sanjoy Sil

List of important Publications:

  1. Possible regulation of trehalose metabolism by methylation in Saccharomyces cerevisiae: Shinjinee Sengupta, Paramita Chaudhuri, Sagar Lahiri, Trina Dutta, Shakri Banerjee, Ramdhan Majhi, Anil K. Ghosh. JOURNAL OF CELLULAR PHYSIOLOGY. Accepted Article on 30.6.2010. Online: DOI: 10.1002/jcp.22317
  2. Purification and Characterization of a Low Molecular Weight Endo-xylanase from Mushroom Termitomyces clypeatus. Dhananjay Soren, Mohanlal Jana, Subhabrata Sengupta, Anil K. Ghosh. Appl Biochem Biotechnol, 162:373 – 389, 2010
  3. Studies on substrate specificity and activity regulating factors of trehalose-6-phosphate synthase of Saccharomyces cerevisiae. Paramita Chaudhuri,Arghya Basu, Shinjinee Sengupta, Sagar Lahiri, Trina Dutta, Anil K. Ghosh. Biochemica et Biophsica Acta 1790, 368 - 374, 2009
  4. Antiapoptotic role of S-adenosyl-L-methionine against hydrochloric acid induced cell death in Saccharomyces cerevisiae. Dipankar Malakar, Anindya Dey, Argha Basu & Anil K Ghosh. Biochim. Biophys. Acta, 1780, 937 – 947, 2008
  5. Aggregation dependent enhancement of trehalose-6-phosphate synthase activity in Saccharomyces cerevisiae. Paramita Chaudhuri & Arghya Basu & Anil K. Ghosh. Biochim. Biophys. Acta, 1780, 289 – 297, 2008
  6. Co-purification of glucanase with acid trehalase–invertase aggregate in Saccharomyces cerevisiae. Arghya Basu, Paramita Chaudhuri, Dipankar Malakar & Anil K. Ghosh. Biotechnol Lett. 30. 299 - 304, 2008
  7. Rapid report: Protective role of S-adenosyl-L-methionine against hydrochloric acid stress in Saccharomyces cerevisiae Dipankar Malakar, Anindya Dey & Anil K Ghosh. Biochim. Biophys. Acta, 1760, 1298 – 1303, 2006
  8. Identification and Characterization of a Sperm Motility Promoting Glycoprotein From Buffalo Blood Serum Mahitosh Mandal, Sudipta Saha, Anil K. Ghosh & Gapal C. Majumder JOURNAL OF CELLULAR PHYSIOLOGY 209, 353 – 362, 2006
  9. Extracellular trehalose utilization by Saccharomyces cerevisiae. Arghya  Basu, Soma Bhattacharyya, Paramita Chaudhuri, Subhabrata Sengupta, &Anil K. Ghosh, Biochemica et Biophsica Acta 1760, 134 - 140, 2006.
  10. Application of HPLC for the analysis of biological samples and drugs. Anil K Ghosh, Nilima Biswas & S. Sengupta In "Bioavailability and bioequivalence in Pharmaceutical Technology" ed. T.K. Pal & M. Ganesan, CBS Pubs & Distri., N.Delhi & Bangalore, pp 37 - 51, 2004
  11. Removal of carboxymethyl cellulase activity from the culture filtrate of Termitomyces clypeatus producing xylanase. Anil K Ghosh, Mohon L Jana, Amol K Naskar, Ruplekha Chatterjee & Subhobrota Sengupta. Biotechnology Letters: 24 (15), 1249 - 1252, 2002
  12. Acid trehalase deficiency and extracellular trehalsoe utilization in Candida utilis Amit Roy, Soma Bhattacharyya, Subhobrota Sengupta & Anil K. Ghosh. World J. of Mirobiology & Biotechnogly: 17, 727 – 729, 2001
  13. Rapid report. Correlation between stationary phase survival and acid trehalase activity in yeast. Amit Roy and Anil K. Ghosh. Biochemica et Biophsica Acta 1401, 235 - 238, 1998.
  14. Regulation of acid trehalase activity by association-dissociation in Saccharomyces cerevisiae. Nilima Biswas & Anil K. Ghosh. Biochemica et Biophsica Acta 1379, 245 - 256, 1998.
  15. Characterization of a xylanolytic amyloglucosidase of Termitomyces clypeatus. Anil K. Ghosh, Amal K Naskr & Subhobrata Sengupta. Biochemica et Biophsica Acta 1339, 289 - 296, 1997.
  16. Possible role of isoaspartyl methyl  transferase towards regulation of acid trehalase activity in Saccharomyces cerevisiae. Nilima Biswas & Anil K. Ghosh. Biochemica et Biophsica Acta 1335, 273 - 282, 1997
  17. Characterization of an acid trehalase of Saccharomyces cerevisiae present in trehalase-sucrase aggregate. Nilima Biswas & Anil K. Ghosh. Biochim. Biophys. Acta: 1290, 95 - 100, 1996
  18. Protein carboxylmethylation in the mushroom Volvariella volvacea. Anil K. Ghosh. Phytochemistry 32, 1093 - 1096, 1993.

 
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Updated on 9th August 2010
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