Myofibrillar proteins mainly consist of myosin, actin and other
protein fragments, in which the content of myosin with two heavy
chains and four light chains is higher. The heavy chain of myosin is
about 200 kDa, and the light chain is 30 kDa, while the molecular of
actin is just about 45 kDa (Li, Zhang, & Ren, 2007). A lot of studies
on the TGase treatment of MPI alone had been reported, which
summarily produced the following detectable electrophoretic
changes: (1) The almost instant reduction of myosin heavy chain;
(2) The marked attenuation but not a total disappearance of actin;
(3) The appearance of TGase-induced band immediately below
200 kDa and the smear underneath the actin band. However, the
protein bands of MPI were affected by raw material origin and
extraction method. The actual changes of MPI protein bands in this
study were basically in keeping with the above conclusions except
the time of myosin heavy chain and actin beginning to disappear
extended to almost 30 min and 60 min respectively and some other
protein fragments involved in the TGase-induced cross-linking
obviously (data not shown).