Iodinated derivatives of vasoactive intestinal peptide (VIP), PHI and PHM: purification, chemical characterization and biological activity

Journal Article · Wed Jul 01 00:00:00 EDT 1987 · Peptides (Fayetteville, N.Y.); (United States)

DOI:https://doi.org/10.1016/0196-9781(87)90042-8· OSTI ID:6080173

McMaster, D; Suzuki, Y; Rorstad, O; Lederis, K

The iodination of vasoactive intestinal peptide (VIP) was studied, using a variety of enzymatic and chemical iodination methods. Reversed phase high performance liquid chromatography (HPLC) was used to purify the reaction products. The lactoperoxidase-glucose oxidase method gave excellent results in terms of reproducibility, iodine incorporation, and yield of the non-oxidized products (Tyr(I)10)VIP and (Tyr(I)22)VIP, and was used to prepare both /sup 125/I and /sup 127/I labelled derivatives. In both cases, direct application to HPLC and a single column system were used. Although the oxidized peptides (Tyr(I)10,Met(O)17)VIP and (Tyr(I)22,Met(O)17)VIP could be generated to varying degrees directly by iodination of VIP, these were most conveniently prepared by iodination of (Met(O)17)VIP. Iodinated derivatives of the homologous peptides PHI and PHM were likewise prepared by rapid, one-step HPLC procedures. The site and degree of iodination were determined by HPLC peptide mapping of tryptic digests and amino acid analyses, and in the case of (Tyr(I)10)VIP also by sequencing. The vasorelaxant activities of the iodinated peptides in bovine cerebral artery preparations did not differ significantly from those of the corresponding noniodinated peptides, with the exception of (Tyr(I)10,Met(O)17)VIP and (Tyr(I)22,Met(O)17)VIP which, unlike (Met(O)17)VIP itself, had slightly lower potency than VIP.

• Research Organization: Univ. of Calgary, Alberta
• OSTI ID: 6080173
• Journal Information: Peptides (Fayetteville, N.Y.); (United States), Vol. 8:4
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PEPTIDES
CHEMICAL COMPOSITION
FRACTIONATION
AMINO ACID SEQUENCE
CATTLE
IN VITRO
IODINE 125
IODINE 127
LIQUID COLUMN CHROMATOGRAPHY
TRYPSIN
ANIMALS
BETA DECAY RADIOISOTOPES
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
MAMMALS
MOLECULAR STRUCTURE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HYDROLASES
PROTEINS
RADIOISOTOPES
RUMINANTS
SEPARATION PROCESSES
SERINE PROTEINASES
STABLE ISOTOPES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques