Preliminary assignments of the aromatic and some methyl group resonances of the ¹H‐NMR spectrum of the oxidized form of uteroglobin

Abstract

Two‐dimensional NMR methods have been used to assign aromatic and methyl group resonances in the 1H‐NMR spectrum of oxidized uteroglobin. Assignments to specific amino acids are based on X‐ray‐determined structures of two crystal forms (C2221 and P21) and on an energy‐minimized X‐ray structure of the C2221 form of uteroglobin. These preliminary assignments are sufficient to probe the interaction of oxidized uteroglobin with progesterone in solution. The protein global structure is unmodified but some direct or indirect conformational changes are induced in the H1H4(H1′H4′) pockets and close to Phe28 by progesterone.

CD studies of peptides that mimic the four helicoidal sequences of the uteroglobin monomer

“…2 (left) and 4) point to the fact that this part of the protein could change its conformation under determined conditions and that cysteine might be involved in this process. These results are in agreement with those found by Jamin et al [34] from a study of uteroglobin by NMR. Thus, their conclusions point to a conformational change in N-terminal and C-terminal helicoidal fragments of the protein by interaction with progesterone.…”