Laxma Reddy

Office:     BSBE
Phone: (612) 625-2466
Fax: (612) 624-0632
Mail:




Laxma Reddy 
Department of Biochemistry 
University of Minnesota Medical School 
4-225 Millard Hall 
435 Delaware St SE 
Minneapolis, MN 55455
Email: lgr@ddt.biochem.umu.edu

 




Biochemical Research Interest

Structure and function of membrane proteins, regulation of cardiac sarcoplasmic reticulum (SR) calcium pump (Ca-ATPase) by phospholamban (PLB).

In cardiac SR, the calcium pump is regulated by a small intrinsic membrane protein phospholamban (PLB). Phospholamban inhibits the calcium pump and upon phosphorylation of PLB in response to beta adrenergic response, this inhibition is relieved. Rate at which calcium is removed from sarcoplasm into SR by calcium pump controls the rate of contraction and relaxation of the muscle. Thus understanding the regulation of calcium pump by phospholamban is important in understanding the entire process of how muscle works. 

Publications:

1. Reddy, L.G., E. Bikshapathy and R. Nagaraj. 1985. Solid phase synthesis of signal sequence fragments employing the transesterification method of cleavage. Tetrahedron Lett. 26:425-4260. 

2. Reddy, L.G. and R. Nagaraj. 1985. Circular dichroism studies on synthetic signal peptides. Biochim. Biophys. Acta 831:340 346. 

3. Reddy, L.G. and R. Nagaraj. 1986. Solid phase synthesis of the signal sequence of E. Coli alkaline phosphatase. Proc. Indian Acad. Sci. 97:71-75. 

4. Reddy, L.G. and R. Nagaraj. 1986. Circular dichroism studies on the signal sequence of E. Coli alkaline phosphatase indicate the presence of both α-helix and β-structure in hydrophobic environments. FEBS Lett. 202:349-352.

5. Nagaraj, R., M. Joseph and L.G. Reddy. 1987. Perturbation of the lipid bilayer of model membranes by synthetic signal peptides. Biochim. Biophys. Acta 903:465-472. 

6. Reddy, L.G. and R. Nagaraj. 1987. Circular dichroism studies on synthetic peptides corresponding to the cleavage site region of precursor proteins. Int.J. Peptide Protein Res. 29:497-503 

7. G Reddy, L.G. and R. Nagaraj. 1989. Circular dichroism studies on synthetic signal peptides indicate β-conformation as a common structural feature in highly hydrophobic environments. J. Biol. Chem. 264:16591-16597. 

8. Viramani, M., R. Srinivas, G.K. V. Rao, R. Nagaraj, L.G. Reddy and G. Saberwal. 1990. Mass spectra of t-butyloxycarbonyl (tBOC) - protected peptides. Org. Mass Spectrom. 5:97-100. 

9. Grove, A., T. Iwamoto, M.S. Montal, L.G. Reddy, S. Marrer, J.M. Tomich and M. Montal. 1991. Towards a unifying structural motif for the pore-forming structure of channel proteins. In Biotechnology of Cell Regulation. R. Verna and Y. Nishizuka , eds. Serono Symposium Series, Raven:New York. 4:89-102 

10. Grove, A., M.S. Montal, L.G. Reddy, S. Marrer, T. Iwamoto, J. Tomich and M. Montal. 1992. Channel proteins: from anatomy to design. In Membrane Proteins: Structures, Interactions and Models. Pullman et al, editors. Kluwer Academic Publishers . Netherlands. 249-268. 

11. Reddy, L.G., T. Iwamoto, J.M. Tomich and M. Montal. 1993. Synthetic peptides and four-helix bundle proteins as model systems for the pore-forming structure of channel proteins. J. Biol. Chem. 268:14608-14615. 

12. Shivaji, S., G.S. N. Reddy and L.G. Reddy. 1993. Fluorescence Studies on the binding of a chemotactic peptide to human spermatozoa. Cell. Mol. Biol. 39:17-179. 

13. Montal, M.O., L .G. Reddy, T. Iwamoto, J.M. Tomich and M. Montal. 1994.Identification of an ion channel-forming motif in the primary structure of CFTR, the cystic fibrosis chloride channel. Proc. Natl. Acad. Sci. U. S. A. 91:495-1499. (Both Montal and Reddy were considered first authors and listed alphabetically). 

14. Murthy, T.R., S.A. Chandani, A. Khar, L.G. Reddy,. and P.M. Bhargava. 1994. Seminal plasmin, a bovine seminal plasma protein, lyses dividing but not resting mammalian cells. Biochim. Biophys. Acta 1221:109-114. 

15.S. A. Tatulian, L.R. Jones, L.G. Reddy, D.L. Stokes and L.K. Tamm. 1995. Secondary structure and orientation of phospholamban in supported bilayers from polarized attenuated total reflection FTIR spectroscopy. Biochemistry 34:4448-445 6. 

16. Reddy, L.G., L.R. Jones, S.E. Cala, J.J. O'Brian, S.A. Tatulian and D.L. Stokes. 1995. Functional Reconstitution of recombinant phospholamban with rabbit skeletal Ca2+-ATPase. J. Biol. Chem. 270:9390-9397. 

17. Reddy, L.G., L.R. Jones, R.C. Pace and D.L. Stokes. 1996. Purified, reconstituted cardiac Ca2+-ATPase is regulated by phospholamban but not by Direct Phosphorylation with Ca++/calmodulin-dependent protein kinase. J. Biol . Chem. 271:14964-14970.

 

Techniques:

Functional reconstitution of membrane proteins   Voltage clamp and single channel recording   Fluorescence spactroscopy
Timeresolved phosphorescence anisotropy  Circular dichroism  Peptide synthesis


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