-transparent.png){kind=logo}
alpha-Melanocyte-stimulating hormone (alpha-MSH, alpha-melanotropin), [Nle4,D-Phe7]-alpha-MSH and related fragment analogues, Ac-[Nle4,D-Phe7]-alpha-MSH4-11-NH2 and Ac-[Nle4,D-Phe7]-alpha-MSH4-10-NH2, were studied for their ability to stimulate tyrosinase activity in Cloudman S91 mouse melanoma cells in tissue culture. All of the melanotropins stimulated tyrosinase activity in a dose-dependent manner. [Nle4,D-Phe7]-alpha-MSH was about 100 times more active than alpha-MSH as determined from the minimal effective dose (MED) required to activate the enzyme above control (basal) levels. The MED of this analogue to significantly stimulate tyrosinase activity at 24, 48 and 72 h of incubation was 10(-11) M whereas the MED of alpha-MSH was 10(-9) M at each of these times. The maximum tyrosinase activity achieved from the time of initial incubation in the presence of [Nle4,D-Phe7]-alpha-MSH was approximately 3-, 5- and 6-fold greater than control levels at 24, 48 and 72 h, respectively. The 2 [Nle4,D-Phe7]-substituted fragment analogues were at least as active as the tridecapeptide analogue and therefore at least 100-fold more active than alpha-MSH in stimulating enzyme activity. These [Nle4,D-Phe7]-substituted analogues were more active in the melanoma tyrosinase assay than in the melanoma adenylate cyclase assay or other normal melanocyte (frog and lizard skin) bioassays.
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
June 1998,
The journal of peptide research : official journal of the American Peptide Society,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
May 1993,
Annals of the New York Academy of Sciences,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
February 1986,
In vitro cellular & developmental biology : journal of the Tissue Culture Association,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
July 1983,
Journal of cellular physiology,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
November 1985,
The Journal of investigative dermatology,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
June 1975,
Nature,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
September 1990,
Photochemistry and photobiology,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
January 1961,
Biologica Latina,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
May 1987,
Molecular and cellular endocrinology,
M M Marwan, and
Z A Abdel Malek, and
K L Kreutzfeld, and
M E Hadley, and
B C Wilkes, and
V J Hruby, and
A M Castrucci
June 1970,
The Journal of pharmacology and experimental therapeutics,
