A cold acclimation protein with refolding activity on frozen denatured enzymes.

We found that a cold acclimation protein from an ice-nucleating bacterium, Patoea ananas KUIN-3, has refolding activity on frozen denatured protein. Based on a SDS-PAGE analysis, we confirmed that the cold shock-treated cells of strain KUIN-3 could produce some cold acclimation proteins that inhibit their syntheses by the addition of chloramphenicol during the cold acclimation. Among such proteins, Hsc25 had refolding activity similar to GroELS. Hsc25 was purified to apparent homogeneity by (NH4)2SO4 precipitation and some chromatographies. The purified Hsc25 was composed of 8 subunits of 25,000 each with a molecular mass of 200,000 and had refolding activity against denatured enzymes, which were denatured by heat-treatment at 100 degrees C, cryopreservation at -20 degrees C, or guanidine hydrochloride, in a manner similar to GroELS. The N-terminal sequence of Hsc25 was Met-Arg-Ala-Ser-Thr-Tyr-His-Ala-Ala-Arg-. Furthermore, Hsc25 had a high level of activity at low temperature (12 degrees C). Also, the dissociation constants, KD (M) as the binding specificity for enolase, mutarotase, isocitrate dehydrogenase, and lactate dehydrogenase were 1.82x10(-10), 4.35x10(-9), 8.98x10(-12), and 3.05x10(-11), respectively. The affinity of Hsc25 for frozen danatured enzymes was higher than the affinity for heat denatured enzymes when compared with the affinity of GroEL. These results are the first report on the characterization of a purified chaperon that was induced by cold acclimation.

[Caregiving burden of elderly caregivers who provide at home care for infirm elderly].

In order to elucidate the degree of feeling burdened and factors affecting caregiving burden of elderly caregivers, a questionnaire survey was performed on 241 female caregivers of infirm elderly. The surveyed group consisted of 138 caregivers under 60 years of age (young group) and 103 aged 60 and over (old group). The major results of this survey were as follows, 1) Conditions perceived as unfavorable in the old group were related to caregiving assistants, number of the family members and health condition of the caregiver. 2) Greater number of infirm elderly with serious ADL problems and higher average body weight of the elderly cared for were seen for the old group than the young group. 3) The old group had a larger number of problem incidents and expressed more eager desire for transfer of elderly to institutional care than providing the young group. 4) A feeling of burden in daily care appeared larger for night care, body discharge disposal and bathing care of the elderly and was more frequent in those above 70 than under 70 years of age. 5) Hours in bed were longer and range of movement by wheel chair was more limited for infirm elderly as the caregiver's age increased. These results suggest that the above-mentioned unfavorable conditions in elderly caregivers promote a state of becoming bedridden and a lowering of ADL ability of infirm elderly.