Chemical modification of muscle protein in diabetes.
Levels of glycation (fructose-lysine, FL) and advanced glycoxidation and lipoxidation end-products (AGE/ALEs) were measured in total skeletal (gastrocnemius) muscle and myofibril protein and compared to levels of the same compounds in insoluble skin collagen of control and diabetic rats. Levels of FL in total muscle and myofibril protein were 3-5% the level of FL in skin collagen. The AGE/ALEs, N(epsilon)-(carboxymethyl)lysine (CML) and N(epsilon)-(carboxyethyl)lysine, were also significantly lower in total muscle and myofibril protein, approximately 25% of levels in skin collagen. The newly described sulfhydryl AGE/ALE, S-(carboxymethyl)cysteine (CMC), was also measured in muscle; levels of CMC were comparable to those of CML and increased similarly in response to diabetes. Although FL and AGE/ALEs increased in muscle protein in diabetes, the relative increase was less than that seen in skin collagen. These data indicate that muscle protein is partially protected against the increase in both glycation and AGE/ALE formation in diabetes.
Alt
Nadja
N
Institute of Food Chemistry, Technical University of Dresden, Germany.
Carson
James A
JA
Alderson
Nathan L
NL
Wang
Yuping
Y
Nagai
Ryoji
R
Henle
Thomas
T
Thorpe
Suzanne R
SR
Baynes
John W
JW
D000818:Animals; D003094:Collagen / Q000032:analysis / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000378:metabolism*; D017127:Glycation End Products, Advanced / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D015227:Lipid Peroxidation; D008239:Lysine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D009124:Muscle Proteins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000737:chemistry / Q000378:metabolism*; D013311:Streptozocin
D017127:Glycation End Products, Advanced; D009124:Muscle Proteins; C033186:fructosyl-lysine; D013311:Streptozocin; D003094:Collagen; D008239:Lysine