scholarly journals Loss of fast-twitch isomyosins in skeletal muscles of the diabetic rat

1984 ◽  
Vol 221 (3) ◽  
pp. 645-650 ◽  
Author(s):  
M Rutschmann ◽  
B Dahlmann ◽  
H Reinauer
Keyword(s):  
Diabetes Mellitus ◽  
Light Chain ◽  
Skeletal Muscles ◽  
Diabetic Rat ◽  
Two Dimensional ◽  
Two Dimensional Electrophoresis ◽  
Slow Twitch ◽  
Normal Light ◽  
Fast Twitch ◽  
Dimensional Electrophoresis

By means of pyrophosphate electrophoresis the myosin isoenzyme pattern of two fast-twitch skeletal muscles (extensor digitorum longus, gastrocnemius) and one slow-twitch muscle (soleus) was investigated in control rats and was compared with that of rats 4 weeks after induction of diabetes mellitus by streptozotocin injection. In the fast-twitch muscles the isomyosin pattern consisting of FM1 (fast isomyosin 1), FM2 and FM3 was strongly affected by diabetes, resulting in an extensive loss of FM1 and a substantial decrease of FM2. These changes were also apparent when the light chains of the fast isomyosins were analysed by two-dimensional electrophoresis: LC3f (myosin light chain 3f) largely disappeared and LC2f was significantly diminished. In contrast, the isomyosin pattern in soleus muscle, consisting of SM1 (slow isomyosin 1) and SM2, was not affected by the diabetic state, and two-dimensional electrophoresis revealed a normal light-chain pattern of LC1sa, LC1sb and LC2s. These results indicate that the isomyosins of slow-twitch oxidative myofibres are more resistant to the hormonal and metabolic disorders during diabetes mellitus than are the isomyosins of fast-twitch fibres.

scholarly journals Phosphorylation in vivo of the P light chain of myosin in rabbit fast and slow skeletal muscles

1984 ◽  
Vol 218 (3) ◽  
pp. 841-847 ◽  
Author(s):  
S A Westwood ◽  
O Hudlicka ◽  
S V Perry
Keyword(s):  
Light Chain ◽  
Skeletal Muscles ◽  
Time Course ◽  
Electrophoretic Mobilities ◽  
Slow Twitch Muscle ◽  
Post Tetanic Potentiation ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Frequency Of Stimulation

The P light chain of myosin is partially phosphorylated in resting slow and fast twitch skeletal muscles of the rabbit in vivo. The extent of P light-chain phosphorylation increases in both muscles on stimulation. Rabbit slow-twitch muscles contain two forms of the P light chain that migrate with the same electrophoretic mobilities as the two forms of P light chain in rabbit ventricular muscle. The rate of phosphorylation of the P light chain in slow-twitch muscle is slower than its rate of phosphorylation in fast-twitch muscles during tetanus. The rate of P light-chain dephosphorylation is slow after tetanic contraction of fast-twitch muscles in vivo. The time course of dephosphorylation does not correlate with the decline of post-tetanic potentiation of peak twitch tension in rabbit fast-twitch muscles. The frequency of stimulation is an important factor in determining the extent of P light-chain phosphorylation in fast- and slow-twitch muscles.

Myosin light chain phosphorylation in fast and slow skeletal muscles in situ

1984 ◽  
Vol 247 (5) ◽  
pp. C462-C471 ◽  
Author(s):  
R. L. Moore ◽  
J. T. Stull
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Skeletal Muscles ◽  
Myosin Light Chain ◽  
White Muscle ◽  
Slow Muscle ◽  
Phosphate Content ◽  
Slow Twitch ◽  
Fast Twitch

The physiological properties of contraction-induced phosphate incorporation into the phosphorylatable light chain (P-light chain) of myosin were examined in fast-twitch white, fast-twitch red, and slow-twitch skeletal muscles in situ. Neural stimulation of rat gastrocnemius muscles between 0.5 and 100 Hz produced an increase in the phosphate content of the P-light chain from the white portion of the muscle, and the rate of P-light chain phosphorylation was frequency dependent. The extent of phosphorylation of P-light chain from the fast-twitch red portion of the gastrocnemius muscle was less. In contrast to fast-twitch skeletal muscle, only high-frequency stimulation (30-100 Hz) produced a small increase in the phosphate content of P-light chain from the slow-twitch soleus muscle. Fast white muscle contained 2.2 and 3.5 times more myosin light chain kinase activity than did the fast red and slow muscle, respectively. The rate of P-light chain dephosphorylation was four times faster in slow muscle than in fast white muscle. Thus the greater extent of phosphorylation of P-light chain in fast-twitch white skeletal muscle fibers may be due in part to the presence of more kinase and less phosphatase activities. Isometric twitch tension potentiation was correlated to the extent of phosphorylation of P-light chain from fast white muscle. The physiological consequences of P-light chain phosphorylation are likely to be of greatest importance in fast-twitch white muscle.

Sialic Acid Dependent Polypeptide Chain Heterogeneity of Human Fibrinogen Demonstrated by Two-Dimensional Electrophoresis

1982 ◽  
Vol 47 (01) ◽  
pp. 019-021 ◽  
Author(s):  
Cemal Kuyas ◽  
André Haeberli ◽  
P Werner Straub
Keyword(s):  
Sialic Acid ◽  
Polypeptide Chain ◽  
Two Dimensional ◽  
Charge Heterogeneity ◽  
Human Fibrinogen ◽  
Two Dimensional Electrophoresis ◽  
Isoelectric Points ◽  
Polypeptide Chains ◽  
Dimensional Electrophoresis ◽  
Chain Type

SummaryHuman fibrinogen was compared with asialofibrinogen by two-dimensional electrophoresis to evaluate the contribution of sialic acid to the heterogeneity of the γ- and Bβ-polypeptide chains.Reduced fibrinogen showed three major variants for both the γ- and Bβ-chains. In addition two minor γ-bands with a more acidic isoelectric point than the normal γ-chains were observed. Electrophoresis in the second dimension (SDS) suggests that these most acidic bands are γ-chain-variants with a higher molecular weight. In asialofibrinogen only two predominant variants with more alkaline isoelectric points were present in each chain type.It is concluded that enzymatic removal of sialic acid partially reduces the heterogeneity of the γ- and Bβ-polypeptide chains of human fibrinogen, but additional sources producing charge heterogeneity must be sought.

Improvement of Two-dimensional Electrophoresis of Rice (Oryza sativaL.) Proteomics

2012 ◽  
Vol 18 (5) ◽  
pp. 819 ◽  
Author(s):  
Yanhua YANG ◽  
Weitong CUI ◽  
Xiaoyong LIU ◽  
Keming ZHU ◽  
Keping CHEN
Keyword(s):  
Two Dimensional ◽  
Two Dimensional Electrophoresis ◽  
Dimensional Electrophoresis
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