Abstract
The composition of muscle proteins and free amino acids in the mudskipper (hibernant fish) were investigated before and after hibernation (maturity period: August, hibernation period: November thru. April). It was found that crude proteins were 17.6% in August, 17.5% in November and 16.9% in April, while among the muscle proteins, sarcoplasmic proteins were constituted up to 19.2～20.4%, 58.8～61.3% for myofibrilla proteins, 11.2～13.2% for intracellular proteins and 7.5～8.3% for stroma proteins. Composition changes of the muscle proteins were hardly noted until November but during the hibernation(from Nov. to Apr.) the amount of the sarcoplasmic proteins and the myofibrillar proteins decreased pronouncedly. As for the sarcoplasmic proteins, 14 subunits were found and among them, the amount of 30 kDa and 46 kDa subunits were found to increase slightly in April compared with those in November, while the amount of 35 kDa and 65 kDa subunits were decreased slightly. As for the myofibrilla proteins, 13 subunits were found and detectable changes in their composition were not observed until November but in April the amount of myosin heavy chain was increased by 3%, while the amount of actin decreased by 3% when those are compared with the results in November. The composition of amino acids in the muscle proteins was hardly changed during the observation period. But there were considerable changes of composition of free amino acids. Glycine and alanine were found to be the major free amino acids. The most striking feature was the changes in the glycine and arginine content: the former, which is a dominant free amino acid, was increased by two-fold in April compared with that in August and the latter was increased by two-fold in November and by four-fold in April. It was also found that the amount of essential amino acids (i.e., lysine and histidine) and others (alanine, glutamic acid, serine, aspartic acid and valine) increased significantly during the hibernation period.
동면어 짱뚱어에 대해 월동전ㆍ후(성숙기: 8월, 동면직전: 11월, 동면직후: 4월) 육단백질과 유리아미노산 조성 등을 각 시기별로 비교, 검토하였다. 조단백질 함량은8월 17.8%, 11월 17.5%, 4월 16.9%이었고 근원질 단백질은 육단백질 전체의 19.2～20.4%, 근원섬유 단백질은 58.8～61.3%, 세포내 잔사단백질과 기질단백질은 각각 11.2～13.2%와 7.5～8.3%를 차지하였다. 단백질 조성을 시기별로 비교한 결과 11월까지는 거의 차이가 없으나 4월은 기질단백질을 제외한 근원질과 근원섬유단백질 2종이 소량 줄었고 조성비로 근원질단백의 감소가 조금 더 큰 것으로 파악되었다. 근원질단백 구성 subunit는 총 14종이 검출되었고 구성 subunit 중 30kDa와 46kDa등의 조성이 11월보다 4월에 소폭 증가하였고 35kDa, 65kDa 등은 소폭 감소하였으나 기타 대부분은 거의 차이가 없었다. 근원섬유단백질은 총 13개의 subunit가 검출되었고 대부분의 subunit 조성이 11월까지는 거의 비슷하였으나 4월은 동면전보다 myosin heavy chain 조성이 3% 정도 늘어난 반면 actin은 3%정도 줄어들었다. 단백질 구성 아미노산 조성은 전기간에 걸쳐 일정하였고 주요 유리아미노산은 glycine과 alanine이었으며 두드러진 특징은 arginine함량이 8월보다 11월이 2배, 4월은 4배 이상 늘었고 glycine도 8월보다 4월이 2배 함량으로 모든 아미노산 중 양적 증가가 가장 현저하였다. 기타 alanine, glutamic acid, serine 및 aspartic acid와 valine 등도 동면기간 상당폭으로 증가하였고 lysine, histidine 등의 필수아미노산 함량도 유의적으로 증가하였다.