TY - JOUR
T1 - Selective modification of tryptophan-150 in ovine placental lactogen
AU - Cymes, Gisela D.
AU - Mercedes Iglesias, M.
AU - Wolfenstein-Todel, Carlota
N1 - Funding Information:
Acknowledgements--We thank Dr J. A. Santome for critical review of the manuscript and Miss D. Beatti for excellent technical assistance. This work was supported in part by grants from the Consejo Nacional de Investigaciones Cien-tificas y T6cnicas (CONICET) and the Universidad de Buenos Aires. The amino acid sequencing was performed in the LANAIS-PRO (UBA-CONICET) (Facility for Protein Sequencing).
Funding Information:
oPL was purified as described by Hurley et al. (1977). The hormone met all the criteria of purity indicated by these authors, although it was obtained in a smaller amount, oPRL was donated by the National Hormone and Pituitary Program supported by NIDKK, the Center for the Population Research of the NIH, and the Agricultural Research Service of the U.S. Department of Agriculture and NHPP, University of Maryland, School of Medicine. bGH was prepared by the procedure of Dellacha and Sonenberg (1964). o-Nitrophenylsulfenyl chloride (NPS-CI) and TPCK-treated trypsin were obtained from Sigma Chemical Co. (St Louis, MO) and trifluoroacetic acid from Baker Chemical Co. (Phillipsburg, NJ). Na125I was purchased from the Comision de Energia Atom-ica, Buenos Aires, Argentina. Acetonitrile was HPLC grade and all other reagents were AR grade.
PY - 1993/11
Y1 - 1993/11
N2 - 1. 1. Ovine placental lactogen was modified by reaction with o-nitrophenylsulfenyl chloride. Fluorescence measurements indicated that one of the two tryptophan residues of the molecule had reacted. Besides, there was some reagent not covalently bound. 2. 2. The reagent was covalently bound to Trp-150. No evidence of modification of Trp-90 was found. 3. 3. Binding capacity to lactogenic as well as somatogenic receptors was diminished but not abolished upon modification, indicating that absolute molecular integrity of Trp-150 is not required for binding. 4. 4. This behavior is similar to that of the tryptophan residues of ovine prolactin.
AB - 1. 1. Ovine placental lactogen was modified by reaction with o-nitrophenylsulfenyl chloride. Fluorescence measurements indicated that one of the two tryptophan residues of the molecule had reacted. Besides, there was some reagent not covalently bound. 2. 2. The reagent was covalently bound to Trp-150. No evidence of modification of Trp-90 was found. 3. 3. Binding capacity to lactogenic as well as somatogenic receptors was diminished but not abolished upon modification, indicating that absolute molecular integrity of Trp-150 is not required for binding. 4. 4. This behavior is similar to that of the tryptophan residues of ovine prolactin.
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U2 - 10.1016/0305-0491(93)90157-Z
DO - 10.1016/0305-0491(93)90157-Z
M3 - Article
C2 - 8281766
AN - SCOPUS:0027373920
SN - 0305-0491
VL - 106
SP - 743
EP - 746
JO - Comparative Biochemistry and Physiology -- Part B: Biochemistry and
JF - Comparative Biochemistry and Physiology -- Part B: Biochemistry and
IS - 3
ER -