Alteration of collagen composition and cross-linking in keloid tissues.
Collagen composition and cross-linking in human keloid and normal skin tissues were analyzed biochemically. CNBr peptides were separated by 2-dimensional (2-D) mapping and high performance liquid chromatography (HPLC). The amounts of type I and type III collagen was quantified by 2-D scanning densitometry of fluorographs of 2-D maps derived from samples radioactively labelled in vitro by [3H]-NaBH4 in dimethylformamide. Keloid tissues contained 31.6 +/- 2.2 percent type III collagen as compared to 21.4 +/- 2.7 percent type III present in normal human skin dermis. HPLC profiles of CNBr peptides showed that approximately 5 percent of the high molecular weight material in keloids is mercaptoethanol reducible, compared to insignificant amounts in normal skin. 2-D maps derived from CNBr peptides of keloid collagen demonstrated thiol reduction sensitive alpha 1(III)-CB9 dimer as well as 24,000- and 32,000-dalton CNBr peptides, which were not mercaptoethanol reduction sensitive in normal skin due to cross-linking via the lysyl oxidase pathway. Also, a group of 20,000- to 25,000-dalton CNBr peptides, in the alpha 1(I)-CB6 cross-linking region were prominent in keloid tissues.
Di Cesare
P E
PE
Orthopedic Hospital, Los Angeles, CA 90007.
Cheung
D T
DT
Perelman
N
N
Libaw
E
E
Peng
L
L
Nimni
M E
ME
D000328:Adult; D000368:Aged; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000032:analysis / Q000737:chemistry* / Q000145:classification; D003488:Cyanogen Bromide; D006801:Humans; D007627:Keloid / Q000378:metabolism*; D008875:Middle Aged; D008970:Molecular Weight; D010449:Peptide Mapping; D011487:Protein Conformation; D012867:Skin / Q000737:chemistry
D003094:Collagen; D003488:Cyanogen Bromide