Sammanfattning

The structures of the bound C-13/H-2 double-labelled [(2' R/S,5' R/S)-H-2(2)-1',2',3',4',5'-C-13(5)]-2'-deoxyadenosine (dAdo) and the corresponding 2'-deoxycytidine (dCyd) moieties in the complexes with human recombinant deoxycytidine kinase (dCK) have been characterized for the first time by solution NMR spectroscopy. Transferred dipole-dipole (DD) cross-correlated relaxation (CCR) and transferred NOE (TRNOE) experiments have been employed to show that the ligands (i.e. dCyd and dAdo) adopt a South-type sugar conformation when bound to dCK. The bound South-type 2'-deoxynucleosides are likely to be in a "near transition state", such that they can be transformed into their 5'-monophosphates by transesterification from the phosphate-donor, ATP. The chemical integrity of the product, 2'-deoxynucleoside 5'-monophosphate, has been unequivocally proven by P-31-H-1 correlation spectroscopy. It has also been observed that the aromatic-H1' NOE crosspeaks are the same sign for the bound acceptor and products, the 5'-monophosphate of dAdo or dCyd and ADP, thereby showing that the acceptor and the products have comparable correlation times, and suggesting that they are all bound to the dCK in a ternary complex. Evidence is presented suggesting two binding sites for dAdo compared to dCyd, which has only one binding site on dCK. Our present understanding of the "near transition state" structure of the ligands in the dCK reaction complex may help the design of new nucleoside transition state therapeutics.

Publicerad i

Journal of the Chemical Society, Perkin Transactions 2
2000, nummer: 11, sidor: 2199-2207

SLU författare

• Usova, Elena

  • Institutionen för veterinärmedicinsk kemi, Sveriges lantbruksuniversitet
    

• Eriksson, Staffan

  • Institutionen för veterinärmedicinsk kemi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Organisk kemi


Publikationens identifierare

DOI: https://doi.org/10.1039/b005732k

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/108054