ULTRASONIC MEASUREMENT OF MELANOSOMES FOR CHARACTERIZATION OF THEIR PHYSICOCHEMICAL STRUCTURE IN B-16 AND HARDING-PASSEY MELANOMAS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 44  (10) , 4337-4341
Abstract
Ultrasonic measurement of the 2 different forms of melanosomes was carried out at 20-300 MHz on B16 and Harding-Passey mouse melanomas which produce ellipsoidal-lamellar and spherical-granular melanosomes, respectively. The structure of the 2 forms was basically amorphous and copolymeric in the molecular dimension of a segment composed of 5-6 zigzag units. A marked difference in particle wave resonance was found around 200 MHz in the 2 melanosomes. Based on the chemical structure of melanin proposed by Hempel, it was indicated that the physical structure of Harding-Passey melanosomes is a copolymer in which melanin and protein moieties run parallel to each other but may bind together at the sites of planar groups, while that of B16 melanosomes is a double-helix polymer of melanin and protein moieties with a screw symmetry of N = 6. This type of 1-dimensional cyclic ordering, commonly known as the Born-Karman periodic boundary condition in semiconductive band theory, may be related to the formation of the lamellar structure seen in B16 melanosomes. [Implications with respect to the use of melanin synthesis and melanosomes in the diagnosis and therapy of cancer are presented].