Characterization of cleavage products in selected human lutropin preparations. A protease-sensitive site in human lutropin beta subunit.
Int J Pept Protein Res
; 27(1): 70-8, 1986 Jan.
Article
en En
| MEDLINE
| ID: mdl-3512464
ABSTRACT
Low molecular weight fragments derived from the beta subunit of human lutropin have been frequently observed. These fragments are detected by polyacrylamide gel electrophoresis in sodium dodecyl sulfate following reduction of the disulfide bonds. A sample of human lutropin was identified that had a major portion of its beta subunit showing this proteolytic nick. Over 83% of the subunit was nicked based on reduction, carboxymethylation, and isolation of the low molecular weight fragments. This preparation had 53% of the activity of an intact human lutropin (radioligand assay). The proteolytic nick in the subunit was shown by N-terminal sequencing of the C-terminal fragments to be derived from three clips in a hexapeptide region (residues 44-49) characterized by hydrophobic alkyl side chains. Specific clips were on the amino side of Leu-45 (8%), Val-48 (45%) and Leu-49 (47%). Thus the proteolytic activity, presumably derived from the pituitary during processing, has a substrate specificity reminiscent of the bacterial protease, thermolysin.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Hormona Luteinizante
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
Idioma:
En
Revista:
Int J Pept Protein Res
Año:
1986
Tipo del documento:
Article