title: Chemical modification of muscle protein in diabetes.
abstract: 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.
authors.affiliation: Institute of Food Chemistry, Technical University of Dresden, Germany.
authors.forename: Nadja
authors.initials: N
authors.lastname: Alt
authors.forename: James A
authors.initials: JA
authors.lastname: Carson
authors.forename: Nathan L
authors.initials: NL
authors.lastname: Alderson
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wang
authors.forename: Ryoji
authors.initials: R
authors.lastname: Nagai
authors.forename: Thomas
authors.initials: T
authors.lastname: Henle
authors.forename: Suzanne R
authors.initials: SR
authors.lastname: Thorpe
authors.forename: John W
authors.initials: JW
authors.lastname: Baynes
mesh_terms: 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
chemical_list: D017127:Glycation End Products, Advanced; D009124:Muscle Proteins; C033186:fructosyl-lysine; D013311:Streptozocin; D003094:Collagen; D008239:Lysine